You should look at the Kensis Advantage, though it may border on too "radically different" for you. It takes a bit of getting used to, but everyone I know who has one swears by it (myself included).
Thanks for the suggestion. The design does seem fairly radical, but I think the price is also too high for me to justify giving that one a try.
How well can you switch to a "normal" keyboard? I worry that with some of the more extraordinary designs switching between them and my laptop or a random keyboard at university would be annoying.
I haven't owned a Kinesis but I've owned and used Japanese keyboards (which have a different layout for many of the symbol keys) and various ergonomic keyboards and found being able to switch between them isn't such a big deal.
And the Kinesis Advantage is programmable as well, so you can redefine keys as you please. For example I moved arrow keys to one side, remapped Delete to Ctrl and changed some alt/cmd keys configuration in thumb cluster.