Dear Lazyweb,
Let's say I was thinking about upgrading the second monitor I have attached to my iMac from a CRT (SVGA) to an LCD (DVI). I want that second monitor to run in 1600×1200 or so, and yet be mirrored onto my TV (projector) via an SVideo cable. Right now, I am accomplishing this by having the iMac's mini-DVI going into a mini-DVI-to-SVGA converter, and thence to an AverKey 300 SVGA splitter, which gives me an SVGA pass-through plus a downsampled SVideo output. (As discussed earlier.)
So, there are cables like this which split DVI into DVI-plus-SVGA, but they only work with DVI-I... and as far as I can tell, the only mini-DVI-to-DVI adapters that exist are DVI-D only (suggesting that perhaps Macs don't do analog DVI output at all?)
So, what's the cheapest way to do it?