2n2222 (TO 18) is a General Purpose NPN in a larger package .  
This NPN transistor is similar to the 2n3904, but can deliver higher maximum current at better efficiency ratings.
The Data Sheet for the 2n2222 is at the following address. 
 http://www.ee.washington.edu/stores/DataSheets/transistors/2n2222.pdf

2n2907 (TO 18) is a General Purpose PNP Transistor - is similar to the 2n3906, but can deliver higher maximum current at better efficiency ratings. This is the complementary transistor to the 2N/PN2222.

Should be available through radio shack. Also available through www.digikey.com or wwwmouser.com . 

Hopefully, that will do it. 
Sorry for the error.

This is a set of common package types taken from the Digikey Catalog.  Sizes are not relative.
For example, the top of the TO-3 package has a diameter of .75 inch.