I was looking forward to Ubuntu Linux 8.10 because it was to have a utility to install Linux to a USB pen drive easily.The utility was certainly there, but the first time I tried it, all I got for my troubles was a message on boot that said the partition was invalid or damaged.
After Googling around, I found one comment on the forum that said the utility is looking for a partition number on the target partition. This applied to me as my USB key appeared to Ubuntu as a FAT32 partition on /dev/sdb. But that partition name describes a device, but has no number.
I booted Ubuntu and unmounted the USB key (Toshiba 4GB). That allowed 'qparted' to delate and recreate a partition on the USB pen drive. This time the partition was called "/dev/sdb1".
I then ran the USB pen drive utility. It said the partition needed to be formatted, so I formatted it as FAT32 and specified 1.5GB of persistent space. Much more than that on a 4GB drive and you don't have enough room to install Ubuntu and the attempt will fail that way instead of the way already mentioned. My first attempt was at 3GB (of 4) for persistent space and the install errored out saying Ubuntu needed another 690MB. Oh. So that would make it about 1.7GB at least.
The install to /dev/sdb1 on the USB drive went fine and within a few minutes I was up and running on a persistent USB install of Ubuntu.
My Acer Travelmate 2483 laptop's wireless is 'B43' Broadcom 802.11g, so I had to connect to the Internet via ethernet into my router, then click on System -> Administration -> Hardware Drivers and download, install and 'activate' to the B43 driver. This went smoothly. A reboot had the driver loaded and in a minute or two I was wirelessly connected to the net.
Even allowing for the stumble over the lack of a partition number and the need to re-partition the key drive, this USB Linux install was my easiest and simplest yet.
Now I just have to figure out how to get the latest kernel update to install correctly. It fails saying it's a LiveCD.
