Hellobee Boards

Where I live, cash is pretty much a go-to gift for big occasions like this. But if you don't like that idea, how about a nice frame or photo album they can use to commemorate the occasion? You could also get something personalized on a site like Etsy.

my family tends to give jewelry. Birthstone pieces are always nice, lockets, bangles, or a charm necklace. You could do a cross but if you're not feeling the religious aspect. My mom always has great luck at the khol's jewerly counter.

Cash is good.
We give checks for all of DH's family occasions (he's Jewish, so for Bris/baby naming/Bah or Bat Mitzvah). We put something funny like, "For med school!" In the notes line.

Cash or check is fine. You can put it into a nice card that just says "congratulations on your baptism" or something like that.

We just got D baptized a few weeks ago, and until then I had NO idea you were supposed to give gifts for a baptism. People were showing up with gifts and I couldn't believe it. Anyway, we got quite a bit of cash, which we plan to put (mostly) into his 529 account for college. As far as we're concerned, cash is always appreciated!

I usually give baby china (for close family) or a silver piggy bank or cup or something. If you are more comfortable with cash, that is an absolutely fine gift.

@doxielove: my LO was given some prayer books, a pewter cup, a jellycat lamb (lamb of God reference), and some money. The book with the horse on it had really pretty illustrations. Both books have some secular blessings/poems. The Treasury book has prayers from various religions.