I want to buy A digital pic frame for my grandparents how many pics can i put on it if it has 128mb of space?

You can literally put hundreds on the frame....IF you resize the images to the native resolution of the frame. Here's why (and why fhotoace needs to read this part). When you take a digital photo, the image file will take up several megabytes in size because it's usually high resolution. However, for display purposes, you don't need all that resolution and hence, much of the data can be thrown away. Most frames are either 640 x 480 or 800 x 600 (unless it's a widescreen frame). If you take your image and save A COPY (never save over the original!) in the frame's native resolution or a resolution lower than that, the file size will be greatly reduced. It's possible to get an 800 x 600 size image that's around 100 kilobits or 10 per megabyte or 1280 photos. One thing to watch out for: making sure you don't get out of whack proportions as the screen tries to stretch or compress the image to make it fit. Just make sure to keep the proportions correct. Often, software will come with the frame to make sure that you can resize the images without getting crazy proportions. Don't use the out of camera full-size files and you'll get plenty of storage space, even with 128 megabytes.

It totally depends upon what size memory card you put in it (or in some cases, USB flash card). Internal memory is too small to mean anything ... I can only get about 32 images on a 128 card. 1GB cards were selling today for around $12, so you can see the difference in storage capacity at a very low cost.