As it turns out, JavaScript on the Centro's Blazer browser does work — and to a surprising degree. The DOM, though existant, presents its own pile of fussy bugs — but I've started feeling out their borders. I'm tempting fate and tentatively trying to use YUI, but think I may fall back to an older-school common.js to build up a collection of things that work.
Next, I try to wedge some form of AJAX into the poor thing. It looks like hacks involving cookies or iframes may be viable, if XMLHttpRequest is unavailable.
All this because I just can't bring myself to wrestling a GCC cross-compiling environment for Palm working on OS X again. Last time I tried that was like 2002, and I almost didn't survive the ordeal. And also, I don't yet want to buy an iPhone.
Oh, and it's been awhile since I really tried some masochistic hacking.