Great guide, thanks, worked like a charm on my E6410 (with Backtrack instead of Ubuntu, but it doesn't matter).
BUT, since our laptops are UEFI-ready, I was wondering if there's a solution to build a pure GPT system. I don't really like the hybrid MBR/GPT solution. I spent the last three days struggling to find a EFI bootloader that would be able to boot Linux and MacOS X, since Windows 7 got his own bootloader inside the EFI partition, with no success. Here's what I did :
1) Booted from the E6410 iso, erased and partitionned the disk with diskutil, installed MacOS X. At this point, the disk is a hybrid MBR/GPT.
2) Booted from a Parted Magic Live USB, in order to launch GNU Parted. I reformated one of the FAT32 partition with parted, it destroyed the hybrid MBR in the process, remplaced it with a protective MBR. At this point, the disk is pure GPT.
3) Booted from the Windows 7 x64 CD, in UEFI Mode. It detects my disk as a GPT disk, so I have the leisure to install Windows.
4) Booted from the Backtrack DVD, installed it without any bootloader (for now). I'll probably install grub2 or elilo as soon as I figured out how they works
Now, I can boot Windows 7 natively in UEFI mode, and Mac OS X with the E6410 iso, and my hard disk is pure GPT. I installed rEFIt inside the EFI partition, and added a rEFIt.efi entry inside the BIOS, but it doesn't boot. I'm still looking for a way to boot everyone from the hard disk. If you have any suggestions, they're more than welcome.