Truth be told, I think this is the best wedding party gift. The price is right, its itty bitty, good for both bridesmaids and groomsmen, and can totally be personalized in more ways than one. Personally, I would love if someone handed me this ipod shuffle:
The ipod above is just $49 at apple.com or just about anywhere ipods are sold. The 4GB below is awesome, as you can have it engraved with a name. I'll say that I am against engraving your names or wedding date on it. I do however recommend pre-loading some music they'll love. If you want to put your wedding "stamp" on it, pre-load it with songs you know will be played at your wedding. Empty ipods are boring without music (and kind of a tease).
Yeah, this is way better than a beer mug or monogrammed tote bag. Been there, done that.