USB Lion Recovery Disk fails to boot
I have done this using the raw InstallESD.dmg image from the Mac App Store Lion installer (NOT the Recovery Disk Assistant) using the following steps:


Drag the InstallESD.dmg image to Disk Utility so that it appears on the side bar
Select your USB drive and partition the drive in to 2 or more GUID partitions
Once partitioning is complete, select the Restore tab
Drag that InstallESD.dmg image from the side bar to the source field
Drag the first partition from the USB drive on the side bar to the target field
Begin the restore process


Once finished you can leave things as they are or re-format the other partition as ExFAT or MS-DOS. However you should be aware the USB drive is GUID partitioned so only Windows 7 is likely to read it properly (I've never tried a GUID partioned USB drive on an XP system). You cannot use standard MBR partitions for the Lion Recovery Partition.