Some XMPP servers support transports or gateways to other protocols (e.g. AIM, ICQ). This is neat because it means you can use a Jabber client to a single server and have that server send and receive messages on your behalf to all of the other IM services you use.
There are a couple of ways to support this but the best way, in my limited, uninformed opinion, is for the client to support XMPP's discovery protocol.
I migrated as many of my IM accounts as I could to Jabber to get around the Yahoo/MSN/WLM connection errors that cropped up recently. My hosting company offers free Jabber server installs, so I added it to an existing server (one-click install), then used Adium on a MAC computer to discover/register various transport gateways with my Jabber account: Yahoo, MSN, Windows Live Messenger, AIM, Twitter, etc. The Jabber support pages indicate available transports include ones for SKYPE and FACEBOOK, but I couldn't get those two to work.
Once that was done, I switched over to the N810, removed all accounts from RTCOMM, added my single Jabber account, and then my IM contacts began to rain down the screen like so many drops into a bucket. . .
The built-in client supports transports, but not discovery. Set up your Jabber account on your computer, set up your transports and then login with your tablet.
Looking at them, Jabber.org says that it is not compatible with the proprietary messengers, such as Yahoo, AIM, and Windows Live. ONE of the USA servers mentioned something about gateways allowing you to do so, but it was just a passing mention.
I'm an utter n00b at this, so maybe someone can make a guide?
EDIT:
Getting to Jabber's development pages, I saw gateways for lots of clients. Only problem...All the pages were dead and wouldn't load.
