The new Ubuntu 12.04 installer is very flash-drive UNFRIENDLY. In prior distro versions, you could boot off of a bootable LiveCD/USB, and plug in another USB stick (larger), and select the USB drive, and install onto it, and the installer would do the partitioning and filesystem mount points automatically for you.
12.04's installer, basically, detects that the PC has a HD containing Windows, and asks you if you want to install alongside windows, install instead of Windows, or "expert mode". No drive selection until you get to expert mode, and then I get lost, not knowing how big the various Linux FS mount points are supposed to be, etc., and even what they are.
It is IMHO a serious defect in the installer, a loss of features in order to "Simplify". Personally, I dislike that. (Along with Firefox getting rid of the Menu Bar by default. That's the first thing I turn back on during an installation.)