I currently have a Foes Weasel going, and I got a new rig. (The 2004 Weyless 67) and I'll be riding the 67 a lot more than the weasel for just about everything. (FR, DH, Trails).

So I decided since the Weasel frame is so nice and small, I am turning it into a Dual Slalom/Mountain Cross bike. Here's what my component spec looks like:
Foes Weasel Frame with a Fox Vanilla RX Rear Shock (5-6 inches of travel)
03 Marzocchi DJ3
Rhyno Lite Front Rim, Mavic Rear Rim
XT Hubs
XT Drivetrain with Deore Pods
Race Face Turbine LP Crankset
DH Cube Stem
Chris King Headset
Shimano Deore Front Disc Brake, XT Pull Rear
Easton Handlebar

I think thats about it. Yes I know that I have a rim brake on the back, it sucks but it works to a degree where it stops me. I can't put discs on the back cause the Weasel has no mounts. So I just forgot about it, and I'll worry about the Rim thing later. I can't do much about it.

What I plan on doing with my Weasel is:
E13 SRS Chainguide. (Run a Chainguide, NON Shiftable)
Remove front shifter and pod
Tune the suspension a tad stiffer. (Does that help speed?)
Setup my seatpost at set back.

Now here are some maybe's:
I want to try and pick up a used Hayes Hydraulic Brake. I don't have a lot of cash, these are just ideas for the future while I am riding the 67 to save up some cash and tune it out so I have SOME reason to ride it.

I was also of thinking of getting some smaller tires. (Aren't DS and MX like 2.35's?) I was thinking Maxxis Mobster 2.35's.

I think thats all. Tell me what you think. These are just ideas, but I am pretty sure I am getting the chainguide. The bike rides really nice. Braking power isn't so great, but I don't think you need hefty brakes for DS/MX. I'll get some faster rolling tires, maybe a brake? Anything else I should consider. And I am not doing any radical changes like a new fork or anything. As is the bike is pretty much a DS bike, I just gotta tune the last things.