Well, a single month of 2xFTE wouldn't make me run out and hire someone... I'd need to be confident that it would continue. But presuming growth or steady revenue is pretty safe in the case of Tarsnap -- most of Tarsnap's revenue comes from storage costs, and in a typical month only about 10% of data gets deleted (and most of that is from machines which are uploading and deleting roughly equal amounts, presumably as part of an archive rotation process).

you seem relatively conservative about this stuff.

Within the limits implied by the fact that I'm running a startup company: Yes, I'm quite conservative in how I do things.

What kind of stuff would you contract out if money wasn't an object?

More testing. Kivaloo development. A GUI wrapper. I might throw some money at a web designer to see if they could make something I like more than the current site (I know you hate Tarsnap's web design, but like the picodollars, it does a good job of attracting the customers I want.) At some point, user support, but probably not yet (I worry that having someone else do user support would lead to me getting out of touch with the user community).

Probably more, but those are the bits which immediately come to mind.