Bebo.com ? - Never.
myspace.com? - Never.
Habbohotel. com/.co.uk - Quite some time ago.
Msn - Regularly.
Aim - Have done so in the past.
Yahoo - Have done so in the past.
Gamesloth.com - Never.
Gameflop.com - Never.
wiicade.com (good for playing games online from your wii) - Have done so in the past.
newgrounds.com - Quite some time ago.