Vernier Software and Technology has been working with the LEGO NXT and their Vernier sensors for months. They are working on a prototype of an adapter that would allow the NXT to work with 40 of their analog sensors. Software blocks that would be used with the sensors and adapter are also being produced. Vernier hopes to have the adapter commercially available early this year.
There are videos of 8 different NXT projects here. I like the "Leveler" (pictured here) that uses a Vernier Low-G Accelerometer as a tilt sensor. This simple robot can carry a cup across uneven terrain without spilling it.
Which is your favorite - and how would you use it?