ConnectBot is a must if you have any SSH needs…. I use this all the time, but as far as productivity goes I can’t say I’m highly productive on my phone other than reading emails.
I also recommend that if you have any interest in rooting your device that you run CyanogenMod (I put together a guide here: http://pseudogen.blogspot.com/2010/06/getting-cyanogenmod-on-your-motorola.html). And purchase the paid version of ROM Manager from the market once you’re on CyanogenMod because the money goes to one of the main developers of the Motorola Droid port of the CyanogenMod ROM
Happy Droid’ing 🙂