I’m a big fan of keyboard navigation these days. I found that having 1 monitor screen with keyboard navigation is more productive than two big monitors with a mouse. Although I have to admit I still like using the Macbook multi-touch trackpad quite a bit.
The Quicksilver interface was definitely an step up innovation from Apple’s spotlight. Although since Leopard it hasn’t been very stable, I still use the Triggers function for shortcuts to my applications. There’s also another alternative – butler, but I haven’t tried it. Last year, I’ve been following this usability company called Humanized and they released a Quicksilver equivalent, Enso, for the Windows Platform. Later it also became free and they ported alot of this idea onto the Firefox mozilla platform.
That is how Ubiquity was born.
I recommend everyone to check this out. It’s definitely natural to a developer to use this kind of interface. I’m glad all the effort that went into Enso was not lost. The response on the mozilla blog post is amazing.
Humanized also seem to be doing some interesting things for Firefox mobile, check it out.
Rex Chung 
Hmm, I’ve heard of Ubiquity this week, but not tried it. I’ve just started using ‘vimperator’ on firefox to get a vim experience in the browser, and it is pretty darn good.
Similarly, I’ve switched from Textmate to vim, and from mac to linux for most of my dev work (using the ‘awesome’ window manager), and like you I’m finding my keyboard driven existence has upped my productivity significantly.
Thats what my colleague uses! He told me about vimperator but it changes the browser abit too much, didn’t want to spend time learning it. He also uses arch for linux.