Being a sad type I measured some current consumption on my 3000.
Default clock speed, PdaXrom installed, no running applications, fully charged battery.
All numbers in milli amps
Off: 35
On with backlight off: 185
On with backlight minimum: 200
On with backlight maximum: 413
THe reast are with minimum backlight.
Wifi inserted and connected to AP: 350
This one was a surprise.
The radio in the wireless takes less than the LED in the wired!!
wired optical mouse, still: 230
wired optical mouse, moving: 280
wireless optical mouse, still: 215
wireless optical mouse, moving: 225
Bluetooth class 1 USB, not connected to anything so searching I assume: 215, 250 when the LED flashes.
XMMS with Mplayer playing a 320 X 240 movie full screen
Not zoomed: 330, 500 ish when the disc is accessed.
Zoomed: 270
Conclusion
Get a wireless mouse
Backlight off and backlight on minimum doesn't have much difference
Zooming the screen saves a lot of power so do your movies at 320x240.
And as an aside one terminal running takes just under 10 ma, that was a shock as well.