The new 650b (27.5") mountain bikes are the next big thing and the Nashbar Bee's Knees Single Speed 650b mountain bike is a perfect example of why. The Bee's Knees Single Speed has the benefits of a 29er without the draw backs. Its bigger wheel size (27.5") means you can roll over stuff that would stop most 26" MTB's, but it is smaller and more nimble than a full-size 29er bike. It's a sweetly spec'd, super simple bike at a value you won't find anywhere else.
But don't just take our word about the Bee's Knees, here's a nice review from Dirt Rag!
"The Bee's Knees is a simple, fully rigid singlespeed with working man's components that, while on the entry-level side, will likely last a while. Notably, the Alex XD-Lite rims, Kenda Nevegal 27.5 tires and FSA Hammer headset all took a beating and remain ready to handle more...
"Overall, this bike is a perfect starter for anyone who wants to jump into the 27.5 wheel category and is a great value at $500."