Currently I only restart to Windows to sync my iPod Touch, and that's because Virtualbox OSE doesn't support USB.
But there's a version, provided by Sun, that supports USB devices.
Uninstall Virtualbox OSE
If you already have Virtualbox installed go to Applications > Add/Remove... and look for virtualbox to uninstall your current version.
I also went to System > Administration > Synaptic Package Manager and also looked for virtualbox to remove every trace of it.
Install Sun Virtualbox (currently v1.6.2 v1.6.4)
Go to Virtualbox download site and go to Binaries (all platforms).
Select your Platform (Ubuntu 8.04 x86 in my case), agree to the license and continue to the download.
After the download is complete start the installer (or double click the .deb file):
$ sudo dpkg -i virtualbox_1.6.2-31466_Ubuntu_hardy_i386.debAnd it's that easy.