I was looking for something and found two eval boards that shows the relative sizes of IC packages. When these packages fist became popular, it was a handy reference. I personally like the SOIC packages because they offer good packaging density, can be hand soldered, and the pins can be inspected without too much special equipment (see board from Fairchild Semiconductor]. The lower photo shows packages from On Semiconductor and are commonly used for Diode, Zener Diodes, FETs, Transistors. These packages offer good packaging density but the power dissipation capability could be better.