Lish via SSH Keys?

You can use the ajax console in an emergency

If you're on Android you can import your private key into ConnectBot and use SSH that way (this isn't for LISH, just regular SSH). I have that on my phone and my Xoom (encrypted). That said, using SSH on a smartphone - even with a hardware keyboard - not the paragon of ease-of-use, but in a pinch, it beats carrying a laptop everywhere.

I have to assume a similar app (or maybe 50 of them) exist(s) for iOS.

'Lish via SSH Keys' is just a way of connecting to the console of your Linode without using a password – the same as you have already set up for regular SSH to your Linode. It doesn't disable password access, so once you have pasted your key(s) into the dialog box and successfully submitted them, change your Lish password to something long and complex -- you won't have to remember it any more.

You can use the Lish Ajax Console (link just above where you found 'Lish via SSH Keys') on any machine that can connect to linode.com. Using keys avoids having to type your Lish password on a machine over which you have no control, but beyond that you are still vulnerable to key loggers so it's not a good solution.

For emergency access without having to carry my laptop (or use a 'strange' computer), I use TouchTerm Pro for iPhone -- there is a free version (TouchTerm) available to try, but I like the extra functionality of the paid app. It has a built-in key generator and can distribute the public keys via email. You can configure it to connect to your server or to Lish, for when something goes badly wrong.