A good friend encouraged me to try Meebo, and online unified instant messaging client. If you live on planet ASCII-only, then that might be fine, but if you work with other languages that is probably a complete deal-breaker. Using Meebo, trying to select other input methods they are just completely grayed out – unable to be selected.
On the other hand, there are two unified instant messaging clients that I’ve found to be very stable, very convenient, and have great i18n support:
Really highly recommend both of these!