Ah, just found it out right after I posted this! They should have the "Pentium Classic MMX" for Socket 7 remake. I know it's pointless, but that's what we grew up on back then!
It's not a new toy, but here's what I got from my officemate last year who dumped that old motherboard and a Pentium III inside. The board is a Gigabyte 6VA7+, baby-AT style, and hmm, an old Riva TNT-2 AGP. Initially it won't start but after 30 minutes of messing around with the jumper settings (and finding what's the FSB and the speed of the P3), it finally booted up. All but I just lost that old big clunky Chicony keyboard with that old DIN connector!! So I just let it stay here - until I get a converter.
I tore out the CMOS battery - gonna replace with a new one. Well, it's old but it's very sturdy. I thought that board is broke for good already.
Thanks! I haven't tested them yet, I don't have much space to put that classic rig. Along the way I'll retrofit the system with cheap low capacity SSD drives. (ebay for 15$)
Here's a review of the TS-E 24mm with an illustration of the tilt/shift effects, but the principle applies to the TS-E 90mm as well.
In short, you can create crazy shallow depth of field which is commonly known as toy town effect, or the complete opposite, increasing depth of field that you can never achieve with normal lens.
It appears you can also use it to correct perspective for architectural shots. I didn't know that was possible...
Haven't had the time to setup some serious shots yet. Just played around when I got the lens and tried something like this: Traditionally, in order to get both frames in sharp focus, you'd either have to use a ridiculously small aperture (i.e. f/32) and have the overall image suffer from diffraction, or take multiple shots and stack them using focus-stacking methods. With t TS-E I just tilt the plane of focus to make it parallel to the frames, and can get away with just f/11.