The digital wallet type devices look like being a good option. One thing I'd really like would be a variation on that idea - a portable CD writer that could burn my images direct onto CD-R. I wonder why no-one has come up with such a device yet - it seems an obvious solution.
I've never used the White Balance on Auto with the D100 apart from a couple of test shots when I first got the camera, just to see if it behaved better than the D1's auto white balance (it does). It doesn't slow me down much because all I'm doing is switching between the presets and that's even quicker on the D100 than on the D1, although I did once leave the command dial on "WB" and try to start shooting: for a moment or two I couldn't figure out why the camera wouldn't work!
I reckon it's still worth doing this despite the fact I'm shooting NEFs and can correct the white balance after the event because Nikon Capture's batch mode will use the white balance embedded in the file by default: this saves me having to correct the settings for 60-70 files at a time.