Recommendations for dressing out of a backpack?

really really bitchin' long underwear, shirt and pants, that can double as chilly weather sleepwear and layer under EVERYTHING YOU HAVE in case of freak coldishness. really good sink wash clothes detergent that is concentrated, kills the funk and rinses out easily. oh and one of those super small, super absorbent, super fast-dry camp towels, in addition to using as a towel they can help you squeeze and wick moisture from washed garments. might want to have one of the short sleeve shirts be a button-down too; then both short sleeves can layer. if you are on foot, and you have laundry that needs to finish drying, it is nice to have straps or bungees or something figured out to hang them on the exterior of your bag. if thats not practical, having to board a bus or something, a sturdy mesh bag that you can secure on the top of your bag that holds the damp stuff is the next best thing for keeping the other clothes from getting funky. if your accommodations include a fan, always aim it at the drying laundry, you will not be sorry. enjoy!

So... what are you thinking for shoes? I really recommend that you have some kind of second pair of wearable shoes (if you can wear flip flops for a full day, great, but not everyone is up for that) because otherwise your primary pair of shoes is going to get super-disgusting. I'm a woman, so, you know, different things work for me, but I find a black or navy lightweight wool sweater to be an incredibly versatile thing to have in my travel wardrobe. It looks nice, it works as an insulating layer, but it doesn't scream "TRAVELWEAR!" And it dries reasonably quickly, though you'll want to squeeze it out in a towel. I don't know for specific recs, but http://www.jcrew.com/mens_category/sweaters/merino/PRDOVR~93973/93973.jsp looks nice, and they also have v-necks and cardigans. Also, this is probably obvious, but make sure every shirt/jacket/sweater matches both your pants and your shorts.

http://www.onebag.com/ is a good resource. I roll everything when I travel. You can get those pants with cut off shorts which I like for travelling. They're usually lightweight. Minimize your colour palette. I swear by http://shop.eaglecreek.com/packing-cubes/l/212. One for t-shirts, one for underwear/socks. http://shop.eaglecreek.com/travel-organizers/l/211 are handy for dress shirts and pants, but not as useful as cubes, I don't think. These are especially useful if you're travelling from place to place - it makes packing and moving on really quick.

For the normal-ish side of things silk will compress down to almost nothing.

For similar ultra-mobile excursions I usually take two undershirts, three pairs of boxer shorts, one or two shirts, one polo shirt, one merino wool cardigan, one pair of lightweight chinos, one pair of shorts, three pairs of socks, nice shoes and sandals or sneakers. You can't dress up a tee but you can certainly appear relaxed and comfortable in a dress shirt. Merino wool is both classy and well-performing and can be had on the cheap at places like HM. (There's no excuse looking like you're living out of a backpack even when you are.) Bring a jacket, base layer, gloves etc. according to the weather you're expecting and just buy extra stuff when you meet the unexpected. Your undergarments should be quick-dry (Uniqlo is great if you have access) for sink washing, for other things it doesn't matter as much. Go easy on electronics as that stuff gets heavy quickly. Just dress smart and don't get too hung up on ultra-performance fabrics and the like. You will be fine.

Tynan has good suggestions for super minimal kit - you could base yours on that and add a few extras if really necessary. Have a read of the last few year's worth to get an idea of what worked well and not-so-well: http://tynan.com/2010gear, http://tynan.com/2011gear, & http://tynan.com/packing2012. Enjoy.

I've fallen in love with http://us.icebreaker.com/on/demandware.store/Sites-IB-US-Site/en/Product-Show?pid=IBQ231. I own a couple of "Tech T Lites," and they are my default travel tees for any weather. If you're not experienced with these, it may be counterintuitive that merino wool and hot weather get along, but these do brilliantly. They don't hold odour (seriously - sweat all day in one of these and it doesn't smell at all the next day), they rinse out great in the sink and dry overnight, and are not at all scratchy or uncomfortable. I've also found, as a Chicagoan with two-plus years in the Brisbane, Australia climate, that soccer jerseys with that "dri-fit" (or similar) fabric are super comfortable in the heat. As far as packing is concerned, I am a fan of using cubes for both clothes and loose items in the bag. http://www.kathmandu.com.au/packs-and-bags/packing-solutions/cells/protective-cell-black.html sitting at the top of my pack's main compartment for my passport, paper travel docs, small items (SIM cards, ear plugs, etc) and all my cash/cards that aren't staying in my wallet. What's nice about this is when you're finally to the hotel, you can grab just your laptop and this cell to throw in the safe and your possibilities of leaving an important loose end behind are minimised.

A long-sleeved button-down shirt can be multiply useful -- traveling by backpack in Mexico, I found a button-down in a wicking fabric to be exactly the right thing. It meant I needed less sunscreen (I wore a tank top underneath; I'm a lady), but had versatility: I could button or unbutton it depending on temperature/need for a breeze, roll the sleeves up or down as necessary, and I felt appropriately dressed basically anywhere I went. Places like Columbia http://www.columbia.com/Men%27s-Silver-Ridge%E2%84%A2-Long-Sleeve-Shirt/AM7453,default,pd.html#detailsTab http://www.columbia.com/Men%27s-Super-Tamiami%E2%84%A2-Long-Sleeve-Shirt/FM7187,default,pd.html#detailsTab designed for outerwear that would also be appropriate in an office environment (although I would definitely take a seam ripper to the tags).

The good doctor has several excellent technical blazers from http://www.acronym.de/, http://www.travelteq.com/apparel, and http://www.arcteryx.com/ProductFind.aspx?language=EN&gender=Mens that have taken him from the great outdoors to the dinner table with ease.