Be careful when doing this. I did this just before I graduated to build up a coupel of pieces for my portfolio and it didn't work out so well. I had one person in particular that I had put a lot of time into the layout on and did a relaly nice one for him, but then he never got around to actually making the site.... made it kind of hard to link to in a portfolio and I had spent a lot of time on it because I wanted a good piece to put in there.
Of course, the folks around here are all pretty good, but a word of warning, no les, since I've seen this posted elsewhere as well.