I just got the Supertooth II, which is an older version (I like the rotary volume button). It links up easily with my Blackjack, and the sound quality is good.
Picked it new off ebay for around $60.
http://www.myblueant.com/supertooth2.htm
Too bad there's no direct voice dial capability on the Blackjack; having to dial the *08 seems self defeating, when I'm looking for hands-free dialing.