Possible Duplicate:
How can I “reboot into” the non-default operating system in a dual-boot configuration?
I'm using a wireless keyboard via bluetooth and therefore cannot use it in grub, so I have to plug in an USB keyboard everytime I want to boot into Windows. AFAK Apple solved this problem by adding adding functions such as "Boot to MacOSX" in the Boot Camp control panel (iMacs come with Bluetooth mice and keyboard) so I was wondering weather it's possible to tell grub to boot Windows next time (and maybe even tell it from Windows to boot Linux next time)
sudo grub-reboot X
where X is the menu entry position (starting with 0 as the first entry)