I have one specifically because I carry it around the house. I'll be listening to a podcast doing work, then carry it into the kitchen to make lunch, then carry it outside to relax. I am thinking about using it as my primary computer speaker as well (especially in light of the MacBook Air's crap under-keyboard speakers).

The sound quality is fine for a pair of small speakers, though they do vibrate a bit. Like ScottC said, I think the Soundmatters speakers are of better quality, but I liked the form factor (big rubber rectangle) of the Jambox.

I've never used it as a speakerphone, so I can't comment on that aspect.

I got mine for $150 on Amazon.