Seatpost maintenance : removing rust I have an aluminum seat post in a steel frame. The post was really hard to extract and I don't want this thing corroding on me.

You've discussed how to take care of the rust on a steel frame and on the use of grease to prevent corrosion. 

Additionally, my seat post seems to be corroded (lightly). 



Any tips on getting that off? Sandpaper/wire brush it off?
Sandpaper is overkill unless it's a very fine grit.  A wire brush would work but it's cumbersome to use on a round shape like that.  Steel wool is perfect.