Christine,
I think it all comes down to how much time you have for your reception. I've been to a couple of weddings where they have slideshows during dinner and they've added a nice touch. But a couple seem to have tried to cram too much during their reception and it seemed very scripted.
Also, if you do, make sure the person who is setting it up during the reception knows what they are doing. My very good friend had a groomsman set it up on his laptop, well it took him like 15min to try to set the whole thing up.