You don't have to use Gnome in Ubuntu. You can always uninstall it and use something smaller like xfce, IceWm, fluxbox, openbox, wmii, awesome, ratpoison etc.
I've definitely used a terminal window, and of course it's
possible to use other window managers, but in Ubuntu, the system and community are designed to create ate a WIMP experience for nontechnical users (I believe they've succeeded admirably). I'm simply suggesting that a minimalist and "Unixy" distribution may be a better vehicle for learning than the most GUI/consumer-oriented distro ever. No one moves to Miami because his kid is a hockey prospect.
I'm not strongly committed to this, but just raising it as a point to consider especially if someone wonders why they feel like they're not learning much Unix/Linux after several months of clicking the Firefox icon on the taskbar.
