i have a machine with win 98 on it. when i go to those sites it installs spyware.i checked the source and it does indeed.
people with windows xp sp2 have nothing to worry since the exploits been patched. if u havent upgraded to sp2 do so,and install all the updates.
if u have win 98 or winme,get all the updates for those OS's and you will be fine.