I've used single touch since Windows 98 and double click feels awkward to me now. I would say that it has to be better for touch rather than quickly trying to double tap your finger quickly.

I switched to single-click shortly after getting started with Tablet PCs. It just made sense to me, and I see no reason to ever switch back.

I tried the same with my work desktop PC, but it got in the way because of all the file renaming I do. Much easier to click a file name to rename it than use one of the other options. Also, I kept opening files and launching apps by accident, even though I don't have that problem when I use a mouse on my tablet.

double click makes more sense for me since i prevents accidental opennings of folders and files. I set the double click speed low and set the spatial seperation high so double clicks with my finger are easy.

on my active tablet i use single click and hover to select, much faster and easier.

For me it depends...
On my Q1 UMPC I use single-click and larger fonts.
On my X60T I use double-click and standard fonts.

For me it depends on how I use the devices.

The UMPC is more mobile and spends most of the time in the car (RAM mount).
The X60T goes any/everywhere with me and I use it more as a laptop and use the touchscreen just for occasional graphics or quick clicks here and there.

I would think the device usage would depend on the setting.

I use single-click/tap since starting with my first tablet in 2004 and it has been part of my setup whenever reinstalling or changing device. On desktop computers I prefer double-click for the same reasons as Sumocat, althoug I also have no problems using the single-click with the mouse on my tablet.

The only problem I have is when remote connecting from my tablet to our double-click servers, the I have to sort of "switch over" to double click in my mind before I can work comfortably. Somehow strange, isn't it?

Andy