Installing xmonad log applet
awick has created a gnome-panel applet to read and display xmonad logHook output, which frees gnome-panel users from the need to run an additional status bar to display xmonad information such as workspaces, titles, etc. See xmonad-log-applet for the project home page.
This page explains how to install and configure xmonad-log-applet-1.0 (or the git version which is currently identical but configured to install to locations compatible with ubuntu karmic.)
Currently none AFAIK. (18 Jan 2010)
Preparing for the install
This is a highly experimental application that's seen very little testing. However it's extremely simple and very unlikely to create problems or break other parts of your system. From here on in I'll assume you're comfortable installing unsupported gnome components outside your package manager's control. Unfortunately so far as I know they must be installed to locations owned by gnome.
To compile the applet you will require a new enough basic gnu toolchain, libc, some additional C development files, and the applet source. To run it you will need xmonad, xmonad-contrib, ghc, and the hackage DBus package. If you have extremely limited disk space it's possible to build the applet on another host and simply install it on the small device, however that's outside the scope of this discussion.
Installing C dependencies
Installing haskell dependencies
Installing the applet
Configuring xmonad to write to the applet
Check .xsession-errors for info from gnome-panel, xmonad, dbus, bonobo, etc. Try #xmonad on irc.freenode.net or the xmonad mailing list for help. Please pastebin or attach your xmonad.hs and what version of xmonad/xmonad-contrib you are using.