Multimon saves you from Apple’s multiple monitor insanity.
Though you'll need to use the Terminal to use OptiPNG, you'll find this tool very valuable for posting or sharing images on the Internet.
Scapple is a promising free-form, nonlinear, mind-mapping text editor that works well on its own or with Scrivener.
Fapptory's Delineato Pro is a new diagramming and mind-mapping Mac app with a clean design and lack of visual clutter
If you need only occasional remote access while around the house, Splashtop isn’t a bad app to keep around.