Good surface mount interboard connector to replace .1" IDC

So now that I am moving from through-hole components on hand-wired boards to surface mount goodies on manufactured PCBs it occurs to me that the .1" IDC connectors and cables that I am using (6, 10, 16 and 20 pin ones, counting the 6 pin Atmel programmer cable) might be able to be replaced with something a little more modern and higher density. But I don't know a lot about this subject. What is a good higher density surface-mount socket and cable system for board interconnection? If through-hole still makes sense for this then suggest that instead, but it has to be denser than .1" IDC. I am thinking logic level here, not a lot of current. I can solder up to TQFP 0.5mm parts now so keep that in mind. If it is no harder to solder than that I can probably make it work. Suggestions? Thanks a lot, again.

Too many to list. Per Newark the common sizes are 2.54mm (which is .1"), 2mm (XBees use that), 1.27mm, 1mm, and .8mm.

FlexPCB connectors are often 0.5mm pitch - quite dense!

Chagrin:
Too many to list. Per Newark the common sizes are 2.54mm (which is .1"), 2mm (XBees use that), 1.27mm, 1mm, and .8mm.

OK, well I just did a bit of a search on eBay to see if there was something cheap that I could use to try this out. Found a product called FFC (flat flex cable) 1.0mm pitch, 8 pins, theoretically ZIF (though I don't see how), 12 cm cables. I bought 20 headers and 10 cables and that should be more than enough to play with. Thanks.