in fact, I'm having a similar problem, only I'm unable to figure out how to switch them in the first place. Right now I'm using GNOME but I'm thinking of switching to Sawfish or something alike. However, in KDE this was fairly simple, you could just add a little application to the panel and clicking on it would swap the keyboard layout.
My question is simply, is there anyway of doing this easily for GNOME and other wm's (other than KDE), or do I have to use a command line everytime I want to switch. In my work I use several languages that require special characters and I want them to be easily available. And I really don't want to go back to KDE (ugh).
Anyone has any ideas on this?