KeyRemap4MacBook, linked by SDub90, should do what you want. Don't be put off by "MacBook" being in the title; it works fine on all Mac hardware.
Firstly you'll need to install KeyRemap, and probably reboot.
Next, disable OS X's default shortcuts for Dashboard, Exposé, etc: System Preferences > Keyboard > Keyboard Shortcuts. Untick the shortcuts to all the F1-15 keys in the Exposé & Spaces, Display, and and Dashboard & Dock settings, like so:
Disable Built-in Shortcuts. These may have slightly different names if you're using OS X Lion ("Mission Control" perhaps?).
Then in the KeyboardRemap4Macbook preference pane, find the "Change F1..F19 key" section and tick "
F1..F12 to Functional".
Although it shouldn't be necessary, you may also need to tick "
Use all F1, F2, etc. keys as standard function keys" in the keyboard preferences.
Please let me know if this works for you; I've been considering a Filco Tenkeyless myself.
Edit: KeyboardRemap should also allow you to reassign the eject key; type "eject" into it's search field and then choose a binding which you like.