Holy crap! I just rooted the device and installed some of the apps you've mentioned on here. Rooting and installing the cyanogenmod in and of itself makes this phone seem like a real beast now. Wow, I thought it was fast before, but DAMN!! Firing up TaskPanel and seeing almost 250mb of free RAM even when multitasking is insane! That himem tweak to allow access to the additional RAM is amazing. This phone absolutely screams now. And the customization offered by the apps you've listed make this thing a dream of a phone. Being able to have the cpu gear down when not in use (sleeping), or after the battery drops below a certain percentage, or hell, any limitations I set, is great. And from what I read, it appears that the cyanogenmod may have the Neon optimizations for ARM architecture floating point optimizations that help with graphics acceleration, so that may explain why program animations that might get a bit slow before now are seriously smooth as can be. I can't choke this phone down now, no matter what I do or how much crap I run. I'm as happy as can be right now with the N1, even more than when I moved to my 3GS from my 3G. It now seems like a BIGGER jump in performance (versus my 3GS) than when I went from the 3G to the 3GS.
Thanks for all the suggestions so far, and keep them coming if you don't mind, if you discover yet more tips like these. It's going to take one hell of an iPhone upgrade in both hardware AND OS to get me to leave this phone when the June/July Apple refresh happens.