I went to Boston Monday for the Enterprise 2.0 conference and I used Hotwire for the first time to book a hotel room. I got a room for $89 ($100 and change with fees and taxes) that was centrally located and very comfortable. You can't beat that price in a major city anywhere.
With Hotwire, you put in your search criteria and it comes up with a list of unnamed hotels organized by price, star rating and location. The trick here is you don't know which hotel you are getting, so it is a bit of gamble in that regard. To reduce the risk, you can see a layout of possible locations on a map along with a description of the likely type of hotel you are going to get (and sometimes you can actually guess based on this information).
I chose a 3-star hotel in the Quincy Market/Financial District of Boston. This put me about 2 miles from the conference which was fine with me (and being near Quincy Market was a nice bonus). I ended up getting the Holiday Inn at Beacon Hill, which sits between the Mass General Hospital complex and Government Center off Cambridge Street. All in all a wonderful location.
The hotel was clean and comfortable. The room had a comfortable bed with puffy pillows. The bathroom was small (the door actually hit the toilet when you opened it), but it was clean with a nice shower, and for my purposes it was fine. All I really needed was a place to sleep since I spent most of my time at the conference hotel.
The conference, by the way, was held at the Westin Waterfront Hotel over by the new Boston Convention Center. Snazzy place, but it would have run me over $400 a night to stay on-site.
By contrast, the Hotwire room was so cheap that I rewarded myself by taking several cab rides, which given the heat of the past couple of days was a huge bonus. Hotwire turned out to be a great choice for me and I plan to use it again in the future, especially when traveling on business.