I've gotten so used to typing commands on my N900 for shell access that on my laptop I would sometimes take longer to type the right commands than I do on my N900.

Personally, I love the N900 keyboard (sure, extra keys would be nice, but I've remapped things so compactly that I'm happier as-is [all command-line-relevant characters are available with shift+fn+key presses, and I can do shift+fn very easily with the one left thumb]). If you go into it with the mindset of something that you can and will get good at with a little practice, and use it somewhat regularly, you'll get used to it within a month at the most.

So, to answer your question Radu: I do apt-get/dpkg stuff by command-line on the phone, I do just about all my archiving/compression/decompression/etc on X-Term. I run aircrack-ng exclusively on my phone, again in X-Term. If you check out my Monitor Clock clock-style in the Advanced Clock Plugin thread - I wrote that entire thing entirely on my N900, using vi in X-Term. After installing PHP and a webserver on the N900, all of my PHP/html/javascript coding has been done in vi-in-X-Term (I did SOME in TXPad for the syntax highlighting, but I'm more comfortable in vi at this point, so I enjoy working in that more than in TXPad). I have coded what little C I coded in vi on my N900 too - I did the same code prior in a Google doc, but I didn't copy-paste it into vi - I just manually typed it back into X-Term's vi. And yes I have compiled my C programs essentially entirely on the N900 - admittedly, the only program I've written aside from a "Hello World" was an attempt to copy qwerty12's R&D Mode Control into a CLI program instead of a GTK+ GUI one. So far I only got it taking parameters, I got stuck at the part where I needed to work the closed source cal library's functions into the program, and haven't had time to get it working since.)

GCC is installed on the N900 by enabling the SDK and Tools repositories (I'm pretty sure GCC is in the SDK one, but Tools is a useful repo to have enabled as well.) You have to manually optify it and its dependencies though. If you'd like I can share a script that I wrote to do the mv and ln -s commands - it's VERY simple to do but saves the hassle if you ever have to do it again or whatever.