When the birthday notification comes up on the side of the homepage, when you click their name _in the notification_ it will automatically send you to their wall in "gift mode". That's how you send the little e-trinkets. They cost money. The best value, IMO, is buying songs. You can buy a song for $0.10 (you have to buy the $0.10 credits in packs of 10 if you pay by credit card, or they're $0.25 credits if you buy 4 for $1 using your phone, so use a credit card). I like to buy songs I think the person may like but not know about.