Quite useful
We had a small mishap at our first hotel stop and had to wash everything we'd brought because of the smoke smell.  My silks and other hand-washables were washed with two sheets of this soap per one or two items (one pair of pants, two tank tops, couple of pairs of socks, etc.) and I felt that they were properly cleaned.  There's basically no suds (perhaps if you used more sheets) and I found that they had to be manually dissolved by rubbing your fingers around the sheets once in the water, but they really seemed to do the job.  Don't try to pull sheets out with damp hands!<br /><br />ETA (Nov 2010):  The above review was for the Laundry Soap Sheets.<br /><br />I recently spent two weeks in London.  The Laundry soap worked well, as usual.  I was not so impressed with the Body Sheets.  Perhaps if you're doing a "sponge bath" type thing, but in a shower I'd put three or four sheets on a washcloth and really didn't feel like it made much of a difference.  Next time I think I'll take a dry cake of body soap instead.  Body Wash Sheets would get a 2 star rating from me.  (I just realized Amazon uses all the reviews for the Travelon products together; they're not separated out by product.)
Rating: 4 stars