Thinking of using them as an extra for the commuter bike, the SL120s. [url= http://www.reelight.com ]Here.[/url]
I asked the same question [url= http://www.singletrackworld.com/forum/topic/reelight-lights-anyone-use-might-be-a-bit-otdarkside#post-1698897 ]Here[/url] but doesn't look like anyone currently uses them.
I've got one of those rear ones on a town-bike, though it might not be an actual Reelight (came with the bike and I haven't paid much attention to it). Had it about 18 months and it still works, just as it did through the cold and wet of the Swedish winter. It's nice not having to worry about it. Just give the wheel an occasional spin to make sure it's working before setting off.
See them all the time when I go to Denmark. Thought it was a neat idea so bought a set for myself. Found them to be expensive, fiddly to set up with QR levers, offered limited visibility (cos the set I had (RL100 I think) only ran off the axle, relatively heavy (if you take the magnets into account) and franky, you get more light and better value from a cheapo set of battery flashers.
Sorry to sound so negative about these, but save your dosh and by some more beer.
buy, not by. Dick.