If you're looking for a way of taking music on the road and don't feel like taking a ton of cables with you or getting down to Shania's Greatest hits through your iphone speaker, this thing will rock your world, and is a massive improvement to most internal laptop or phone speakers, though does have a limited range in terms of highs and lows.
The Z515 has a 10 hour rechargeable battery and despite daily use, I have yet to see it complain of a low battery. The music was clear and loud enough to fill a hotel room, though as I mentioned before, its not on par with dragging your 7.1 PC speakers with you.
It comes with a USB dongle that fits neatly in the back of the unit, and on windows 7 it found the drivers automatically and was ready to go in under a minute, alternatively a 3.5mm mini jack can be used to plug directly in from mp3 players.
The little mentioned Bluetooth support works well too, while I didn't have an iphone to test it on, two android phones (HTC Legend and Motorola Defy) both found it and played local music fantastically, though it did struggle at times streaming music over wifi (both Bluetooth and wifi use the same frequencies, so interference was expected) - simple fix was to use Spotify and download/cache the playlists we wanted prior to hitting play.
The one thing that I was disappointed with was the case, as a travel product, it would have been nice to see a little more thought gone into this, its too long and quite thin, I'll most certainly be looking to find a more suitable case for future travels.
Bottom line, the Z515 is a great portable speaker and will be traveling with me on holidays and road trips alike, but should be considered a much better option than laptop/phone speakers.