Nambu has an intuitive interface and makes Twitter easy to manage without taking up a whole lot of digital real-estate on your screen. In an early beta at the moment, it will also support Ping.fm in later versions. At the best thing about it is the price: free.
CRM (customer <or in this case, contact> relationship management systems) and database systems are not just for enterprises but for consumers as well. Facebook does a really shoddy of organising your network and PIMs like address book.app or Entourage will only go so far. Or if like me you have more records than you know what to do with, you can catalogue them to supplement your recall. (If I’d have done that I won’t have picked up two duplicate St Germain import 12″s that were ridiculiously over-priced.)
Most full-blown database applications can be rather involved and complicated for most home tasks. This is where Bento comes in, it is absurdly easy to use with a wizard application, but at the same time it isn’t patronising like other applications. There are a number of templates that cover a number a wide range of home uses.