MSN increase contact list allowance

I just heard that you can now have 600 contacts on your contact list. Great. This means the new gui code is going to have to be that much more efficient.
I still need to find a solution for truncating nicknames, other than(p.o.c):
foreach contact $contacts {
for i 0 to end {
set width [font measure [string range nick 0 $i]]
if $width > [width of groupbox]
then set nick [string range nick 0 [expr $i - 1]]
}
UpdateNicksOnCanvas
}

Doing that for 600 nicks is not going to be fun.
Oh well, I'm sure I'll come up with something.