Koolim.com works as a messenger and his advantage is that you don't have to install any messenger program. The only thing you have to do is enter in the website (Koolim), and then you will be able to use a lot of messenger accounts: MSN , Yahoo , Gmail (GoogleTalk) , AIM , ICQ , Gadu-Gadu and XFire.
Well, this is an excellent page, very useful and has a lot of extra options. You can find your contacts there and then you can have your conversations ( Chat ). Koolim is a Website like Meebo , Iloveim , Mabber , Ebuddy , Imo , and so on , and all of them are really great and they have a lot of extra options. On Shvoong there are some reviews of those pages, and probably they will be very useful for you.