It can be as easy as tacking up a few old favorites that have been sitting in a drawer (bungee-jumping, wine tasting, skinny dipping?) or as high-tech as you want.
I did this for our dating-aversary using Kodakgallery.com a few years back and it was a big hit (still on our wall!). If you go this route, you’ll want to pick a square number (4, 9, 25…) to avoid the weird repeat feature. You can use as few as four pictures or as many as a hundred.
Looking for other ideas? Here are 50 Ways to be cheap on Valentine’s Day without looking cheap.