The Tech Report has a review up of the Asus CT-479 device that allows you to use the Pentium M processor on various Pentium 4 socket 478 motherboards.  You can check out my review for comparison too.
Compared to other available Pentium M desktop solutions, the CT-479 is compelling. Currently, the CT-479 is available for approximately $42, and compatible motherboards are available for as little as $80-85. For that price, you get dual channels of DDR333 memory and the ability to raise the CPU voltage until the blue smoke escapes. Neither of these options is available with dedicated Pentium M motherboards, and the CT-479 is cheaper than those motherboards.