I'm finding myself burning a lot of Debian CD's lately and I figured it's time I left the 90's and burnt these images to USB instead.
Debian CD and DVD images can be written directly a USB stick. Hit Section 4.1, "Official Debian GNU/Linux CD-ROM Sets" to get a CD or DVD image or as I have been doing, pinching them from the Debian installer dev images.
Once you have your ISO image of choice, you can blat it to the USB disk directly with:
# cat debian.iso > /dev/sdX
# sync && sync
I probably should have said this first but it will wipe your entire USB stick, so make sure there's nothing there you care about. Also the X is /dev/sdX is a substitute for the real letter of of your USB drive ie: /dev/sdb whic can be identified by running dmesg | tail directly after inserting the USB drive.
$ dmesg | tail
[21497.162053] sd 7:0:0:0: [sdb] Write Protect is off
[21497.162062] sd 7:0:0:0: [sdb] Mode Sense: 23 00 00 00
[21497.162723] sd 7:0:0:0: [sdb] No Caching mode page present
[21497.162732] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[21497.167587] sd 7:0:0:0: [sdb] No Caching mode page present
[21497.167598] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[21497.170363] sdb: sdb1
[21497.173837] sd 7:0:0:0: [sdb] No Caching mode page present
[21497.173856] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[21497.173868] sd 7:0:0:0: [sdb] Attached SCSI removable disk
Happy imaging :)
This was lifted heavily from 4.3. Preparing Files for USB Memory Stick Booting in the Debian GNU/Linux Installation Guide.