What can I do for Valentine's day for my guy?

We've been together almost 4 years (anniversary is 4 days before Valentine's Day), and we just got engaged over the holidays. I want to do something nice for him, because he's really romantic and stuff (I'm just pretty much practical) and I noticed that he updated his MySpace to say "10 more days!" and put "excited" or something like that as his mood yesterday. So I know he's looking forward to the day, and I want to make sure I do my part to make it special. I don't know if he's planning a surprise, but I need to take that into consideration because I'm no good at pleasantly surprised reactions - you'll never catch me jumping up and down with glee. I want to be sure that I have a satisfying reaction to whatever his plans might be, and I would like to also have something nice to surprise him with.

I know I'm entirely too analytical for this... but I'd like to try, because I do care immensely and making him happy makes me happy.

Any ideas? He's into movies, sci-fi, selling diamonds (he's a jewelry consultant, I think that's why he's so into romantic stuff), and um... well? I dunno... I just want to do something nice for him.