Weechat 0.2.3-2 doesn't work on the WL500g out of the box, because there are some missing dependencies you might need to install:
ipkg install gnutls
ipkg install libtasn1
ipkg install libgcrypt
and finally:
ipkg install weechat
To start weechat run e.g.:
weechat-curses irc://nickname@irc.xxxxx.net/#channel
some commands that work:
/quit ->disconnects from server
/away message ->set away status
/away ->set available
/names ->show names