I was getting tired of burning CDs every time I wanted to reinstall using latest daily build, so I decided to try using a USB Flash drive. It works perfectly and now I install Ubuntu in ~5 minutes and without needing to burn a CD and it's a lot easier to carry around than a CD.
Steps for doing this from Windows:
- get a good USB Flash drive - they can vary enormously in performance so do some research
- format to FAT32 with HP USB Disk Storage Format Tool
- burn ISO with UNetbootin
- change HDD boot priority in BIOS so that USB is first (see your mobo manual for help on that)
- reboot and install Ubuntu as usual - except it will be *much* faster than usual with a CD
Note: you can still store stuff on your bootable Ubuntu USB drive - just create extra folders as necessary.