What are fun new activities my husband and I can try together?

Learn new board games. If there isn't a hosted tabletop gaming meetup near you, you can just order a new http://boardgamegeek.com/geeklist/164769/best-two-player-husbandwife-games and invite people to your place or to a nearby park, library, etc.

We enjoy this kind of thing too, so these are things my husband and I have done in the last few years: --Watching Tony Zhou's http://everyframeapainting.tumblr.com/ video essays about techniques in film directing and then discussing them; then we watch a movie together and "apply" what we learned. Each video essay is relatively isolated so it only takes abut 20 minutes and although they don't build on each other they build together. We often go on a walk somewhere for the "discussion" part. (As an aside, we both thought film critique would be the most boring thing ever and now we're both regretting not taking a class in college.) --We've done a few "classes" together from websites like http://ocw.mit.edu/index.htm. They're serious classes but you only need to take them as seriously as you want to, so for example we did a business and a math class together doing every assignment and taking the exams to measure what we learned, but we've also just watched the videos for several of the fine arts/humanities classes. --We learned how to play Go together. (on preview, seconding Bentobox) --I know you like hands on hobbies, so maybe you'll enjoy this: We got an http://arduino.cc/en/Main/ArduinoStarterKit and worked through the projects together. (We did the same thing with http://www.raspberrypi.org/help/what-is-a-raspberry-pi/ and built a weather station together, although that might be a lot of programming from scratch learning for you?) -We've also built/made a few things from the Make Magazine series, which involved learning new things. --Birding! Neither of us are serious about it, but it's been fun taking a few hours walk or hike in various places with a basic birding book and some binoculars. There might be Birding Basics classes in your area. --We both love the outdoors and giving back, so we often volunteer at various organized clean-up/trail-building/support activities. --The Appalachian Mountain Club has a http://www.outdoors.org/recreation/activities/washington-dc.cfm with various organized activities and classes in the D.C. area. --Adding to that, REI stores near you will offer both paid and free classes for outdoor activities. (I just plugged in a random DC area zip code, buthttp://www.rei.com/stores/baileys-crossroads.html, scroll to the Outdoor School section.) --A photography class

Archery!

Glass blowing (or welding) http://www.dcglassworks.com/index.php?option=com_wrapper&view=wrapper&Itemid=20 also look pretty cool.

If you enjoy sailing, you might like building your own boat. My wife and I did this one winter and now we have a sturdy dinghy for the boat. The process is quite forgiving and you improve as you go. Lots of youtube videos for technique and inspiration. http://smallcraftadvisor.com/scamp-sailboat/ http://www.bateau.com/

Also, how about ceramics classes? Either a beginners wheel-throwing class, or often can sign up for an 8 week class that teaches you hand-formed pots, slab construction, basic tiles, and a bit of wheel work. Generally this also involves access to the studio to make anything you want outside of class hours. Something like this is a lot of fun; if you do holiday gifts for a lot of people, this could be an opportunity for the two of you to spend a weekend churning them out. I haven't looked it up, but ceramic places are plentiful enough that there's probably one closer to you than a random "DC" google result.

My husband and I started trail-running together about a year ago. Since you like walking/hiking and skiing, you might enjoy that. I know, it sounds like incredibly hard work, but it actually isn't. We started off running some local 2km circular scenic walking trails. 2km takes about 15-20mins max. Neither of us ran before, so we did couch25k, and because it's off road you get plenty of breathers at stiles and gates and "navigation" stops. It feels much less competitive than road running - no one-upmanship about splits or speedwork. It's nice to build up to long distances together, running with a buddy is a lot of fun, it's scenic, you notice nature a lot more, and you do feel a sense of achievement after you've slipped and slided 10miles through a muddy field and nearly fallen in a stream and then finally get back to the car for your lunch (finishing at a pub is another good option). I am still a really crap runner (very slow) but it our runs together are now one of my favourite things. If you've enjoyed skiing you should think about running some of those same trails in spring. You can run slowly and take breaks. Start with short distances and flat routes. Nobody will see you (I hardly ever see other people running on trails). It wil be a surprising amount of fun.

You're in luck if you're open to learning more about mushroom hunting. Washington DC is home to one of the http://mawdc.org/. They frequently have wonderful guest speakers (Gary Lincoff, a celebrity in the world of mycology, is speaking on April 7th, for example). For the price of a membership you're eligible to go on any of their mushroom forays and learn all about the weird wonderful world of mushroom foraging. There really isn't anything quite like it, and it definitely fulfills a lot of your requirements. Spring is a great time to get started as morel season will be starting in April or May. Some of my favorite people are folks I've met at various mycological society events. Dave Arora's classic http://www.amazon.com/exec/obidos/ASIN/0898153883/metafilter-20/ref=nosim/ is probably the best $15 investment you can make. It's not too big, not too small, and has some great images. Perfect to throw in a bag when you go on a walk in case you spot something. It's slightly more focused on the west coast, but it covers many of the major species that grow back east. My personal favorite mushroom guide for the Mid-Atlantic is a book by http://www.amazon.com/exec/obidos/ASIN/0813190398/metafilter-20/ref=nosim/. It's a little more advanced, but hot-damn if it's not one of the best mushroom guides in existence. Beautiful images, well-written and incredibly thorough.

A cheaper option for art classes would be a one-shot thing like https://www.paintnite.com/pages/events/index/dc that guide you through a acrylic painting in one evening. (also, see groupon for discounts on this or similar services!)