<human>: Could you distill the essence of the text into 1-3 sentences?

Ok, so here's the situation.  I've known this couple for about two years, this is the first wedding (as an adult) that I've been invited to.  They know me pretty well, and as such, they know I do not have much money, so I know that they aren't expecting anything big.  My girlfriend thinks we should get them a useful gift, because married couples are of course in need of stuff, and most likely are registered somewhere.  However, it's not like we can get them something like a washing machine or something, whatever we get would have to be small, and I think something that's small and useful wouldn't have the same personal impact, and really won't help much.  The other route, which I think we should go, would be to get something nerd-related; they are fans of Avatar, DnD, Doctor Who, things like that (it was actually overhearing them talking about Avatar that lead me to talking to them when I first met them), which would have more of a personal aspect, and would most likely be cost-effective.  Which should we go with, and what ideas might you guys have for specific gift ideas?
<bot>: Going to get a relatively inexpensive wedding present for two geeky friends, should we get a useful or a geeky gift, and what ideas might you have for specifics?