I really like all these favor ideas! I love the Christmas ornament idea-- that's awesome! However, I would agree with others on here that it can take a while. We were in Disney last week and it took a couple of days to get our ornament personalized.
We're still pretty far out from our wedding (2008)

, but we're planning on giving a donation to St. Judes Children's Research Hospital in honor of each guest (a few dollars per guest), and then they give you a bookmark or scroll to give to each guest telling them what you have done. There is no minimum donation, but we just decided we would give as much as we would have spent on regular favors. Anyone else doing this?
I really haven't kept most of the favors I've gotten at weddings (unless they were yummy snacks or someone really close to me), but we thought this would be memorable and a really good cause.
Just food for thought. A lot of organizations offer this service now as it's becoming increasingly popular.