Charging - from wall, USB and solar?

[PyroPcon]

I just recently built my first MintyBoost and it seems to be working great! (The IC gets quite hot when charging my iPhone 4 and the standard Duracell ProCell AAs got warm, but I understand this to be normal as long as the "sizzle" test for the IC is good).

What I would like to do is to add in the ability to use a set of rechargeable AAs and to add a small solar panel to the top of the case for a "trickle" solar charge, and to also add in the ability to charge via USB and a wall adapter (adding a barrel-jack to the minty boost and using a wall wart or similar style transformer).

What would be the best way to go about doing this? I am fairly new to the world of creating my own electronics. I know there is a LiPo battery pack with solar charger set of instructions and such on the website, but I would like to keep to the 2 (or maybe 3) AA batteries so that as a last resort to charge I can buy a set of AAs and chuck them in.

Where would be the best place to begin here? Taking all suggestions!

[adafruit_support_bill]

If you want to stick with NiMH rechargeables and you are happy with trickle charging, this is a nice tutorial to start with : http://www.evilmadscientist.com/2008/si ... -circuits/