Prompt from Panic does SSH on iPad and iPhone
Described by developer Panic as "a clean, crisp, and cheerful SSH client: it helps you when you need it, and stays out of your way when you don't," early reviewers seem to like it a lot.
Panic says the app is "for system administrators, web developers, movie-style hackers ('Let me just TCP/IP into the UNIX port!'), or any person who needs to connect remotely and type some magic."
It seems reasonably priced at US$4.99. Let us know if you've tried it.