SSH keys from USB Stick

I have a couple of desktops, a couple of laptops and a netbook. Some of these devices still run windows. I use these machines to connect to Launchpad, where my projects are hosted. I'm really starting to fill up the SSH keys section on Launchpad, and I was wondering - if the SSH (private key) relates to me, then I should have a single identity right?

I know there is likely to be a religious flame war here, but I was wondering if I could do something similar to this : I'm wondering if I can create a USB stick - which literally has my certificate installed. This way as I move between machines I can just plug in the USB stick, enter the passphrase and I'm good to go. I could add Putty and the puttyAgent stuff (portable?) on there to allow me to run on windows machines.

This would reduce the number of ssh keys down to 1 - representing me, rather than

• me on a windows laptop
• me on the ubuntu session on that same laptop
• me on a netbook
• me on a desktop" and so on...

Yes, but not on a FAT filesystem. ssh will only use private keys with permissions set to 400 or 600, but FAT doesn't truly allow for this.

To get around this, I made several partitions on my USB key. This gives me a Linux partition for my OpenSSH keys, and a FAT partition for my PuTTY keys. I can then use ssh-add/pageant to load the appropriate key, and connect without specifying my key location.