Kismet and GCC4
dr
While Kismet CAN compile with gcc4, there doesn't seem to be any benefit to doing so.
Infact, gcc4 has a negative impact on performance.

Feeding an 11mb capture file to Kismet compiled with gcc3.3.5:
real    0m1.541s
user    0m1.195s
sys     0m0.298s

Feeding that same file to Kimset compiled with gcc4.0.0:
real    0m2.904s
user    0m2.483s
sys     0m0.281s

After playing around and enabling SSE and SSE2 optimizations:
real    0m3.098s
user    0m2.762s
sys     0m0.278s

Thats right.  It got SLOWER.

The fastest performance was with -O3, -mtune options, and -funroll-loops... and it was
still slower than -O2 under gcc 3.3.5.