SwitchResX allows not only for resolution switching for any resolution but you can also set app triggers, so for example starting lightroom switches to 2880x1800 automagically, as well lots more control...
The default resolution is actually 2880x1800 with all applications running at double size. Things look like 1440x900 size-wise but for example if you set a 2880x1800 wallpaper it will use the full resolution. The same applies for viewing images etc. in retina-aware applications like iPhoto and Aperture.
I seem to be the only person able to work very happily at 2880x1880, haha. I love having a lot of screen space and, while 1920x1200 is far easier on the eyes at first, it just seems that everything displays too large for me now - even on a 15" screen! I'm feeling very comfortable at 2880x1800 and love the amount of space that I'm provided with without sacrificing, for my eyes anyway, readable text.
On the topic of this thread, I like SetResX. It has a lot of resolutions to pick from, including the obvious 2880x1800. It sits as a lightweight menu bar app for quick switching and it costs nothing. However, I've noticed that some resolutions (oddly, including 1440x900) display as if they were on a normal screen when you switch to them from SetResX rather than System Preferences - not Retinised at all. But 2880x1800 looks just fine and this app should suit your needs.