I use Jawbone with iPhone and it works great. Actually sounds lot better then with my old phone or through iPhone speaker. Jawbone key point is noise canceling technology. This is the only BT headset with the vibration sensor which sits on your cheek and detects vibrations created by your voice. It then cancels surrounding noise.
You have several earloops and earbuds to choose from (they come with it). Those did not quite work for me and I used another solution circulation online – Jabra EarGels which you can get for around $6 at Radio Shack or somewhere else. You use smallest round earbud from Jawbone and insert it into one of Jabra EarGels and just have to line up the holes otherwise you will mute the sound.
You end up not having to use any earloop and the Jawbone sits nicely in your ear. Sound quality is great, I had to turn the sound level down on the iPhone. You can glue earbud to the EarGel for a good fit. You can see pictures here:
Checkout the Jawbone BT it's awesome! - Page 3 - BlackBerryForums.com : Your Number One BlackBerry Community
I had Jabra JX10 – great and small but people could not hear what I was saying since it was not extending far enough to pick up my voice. Jabra BT5010 looks interesting. Its features list “wind noise reduction” but not adaptive noise cancellation available only on Jawbone. Surprisingly BT5010 is little heavier then Jawbone which is sizable to me. I am not impressed with BT5020.