My favorite IRC client is "irssi" because it only requires a shell / terminal window to run.  I can leave it running on a reliable machine and logged into the IRC network for long periods of time. Staying logged into IRC allows me to catch up on recent activity in my favorite channels whether I am at home, at work, or on my Droid.

Many people use "screen" to detach from their remote SSH login sessions and re-attach from a different computer.  I found that screen has some quirks with irssi and tons of features that I do not use.  A simpler alternative to "screen" is "dtach".

Here is how I use dtach:

Create a new dtach session on a stable machine:

  dtach -c dtachbashirssi bash

  irssi

 I start a whole bash shell rather than just the irssi program so I can exit irssi as needed (to test new irssi config files, etc.) and then do not need to create a new dtach session, I just run irssi again from inside the existing dtach session.

 Once irssi is running, use CTRL-backslash (^\) to detach. After the dtach session is detached, it is safe to log out of the server and log in from somewhere else.  To re-attach, SSH back into that stable computer and run

  dtach -a dtachbashirssi

On my Droid, I use the ConnectBot SSH client to connect to the stable computer running my detached session. The missing keys on the Droid can make dtach and irssi a little bit challenging, but not impossible.

The default detach ^\ key combination can be accomplished in ConnectBot on the Droid by using the following:

Press center DPAD (this starts the CTRL key sequence), then press ALT-Shift-forwardslash (ALT-Shift-/).

It is possible to re-map the magic detach key when starting dtach (read the dtach man page for more info), but I had a little trouble with this on re-attach.

If I'm on my Droid I just want to cycle quickly through my favorite channels to see if there are any interesting discussions going on.  On a normal computer, I tend to use the ALT-numberkey combination to switch between windows... e.g. ALT-5 takes me to the fifth irssi window.  I have not figured out how to do an ALT -numberkey sequence on the Droid since the Droid uses the ALT key as a local keystroke modifier to type regular numbers.

Another way to switch windows is by typing the irssi command:

/window 5


Too slow!

There is a third way to switch windows... ESC-numberkey (ESC-5) has the same affect.   To switch to a particular irssi window on the Droid, I use the ESC-numberkey combination.

Press center of DPAD twice (this sends the "Escape" key), then press ALT-numberkey to switch to the numbered window.

The Droid double-tap on the DPAD to create "Escape" in ConnectBot is also crucial when editing remote files in vi or vim.  Additional information about ConnectBot is available in the project wiki: 

http://code.google.com/p/connectbot/w/list

Update:  Another important key for working in the command-line is the "Tab" key for file/directory name auto-completion.  Use the "Shift" key on the right side of the Droid keyboard to send the "Tab" sequence.