Almost two years ago I discovered James McCombe's GLTerminal. Some people hacked it to work with Tiger, but I (and others) discovered after upgrading to Leopard that the Classic Terminal view was oddly scrambled, so to fix it I rearranged the character bitmap, as you can see under the cut:
( a tale of two character maps )

new and worksafe

As others noted, the original icon was a little over-the-top (jwz quote: "most inappropriate fanboyriffic application icon evar."), so I made it something more work-safe, a VT220 screen with "GL TERM" in green text.

old and "animeriffic"

To make Classic Terminal mode work (the pictured green-phosphor look) you still need to open the Preferences and re-select the "Classic Terminal" plugin, then click Save. I re-ordered the tabs with "Renderer" being the default, so at least you don't have to click on the Renderer tab like you used to; click-count - 1. If someone could reverse-engineer it so this step wasn't necessary, that would be nice. If James McCombe would update it (or even release the original source), that would be even better. Petition him via email, if you like.

Oh, and lastly it works pretty well with Spaces in full screen mode, though the window doesn't display right when looking at all your spaces (not bad for an app made in 2002, five years before Spaces was even developed).

Download GLTerminal updated for 10.5, sil vous plait.

EDIT 20090904: it still works fine on Snow Leopard. fyi, on my Macbook Pro 13" it pegs the CPU at just under 10% usage in top.