I have a Dell mini 9 which came with a Broadcom wireless card. I used Ubuntu 8.10 on it for a while. The Broadcom STA wireless Driver worked on it sometimes but when I upgraded to Ubuntu 9.04 it wouldn't work at all. I fixed the problem by spending £15 on an atheros wifi card.
Atheros cards have much better linux support. They work well with the in kernel driver, no closed source firmware or drivers required. Avoid Broadcrap