Does ClockworkMod Recovery's "Wipe Data" command also wipe the SD card? I've been playing with rooting and custom ROMs for a while now. I'm fairly comfortable and knowledgable about it all. However there is one thing I haven't really found the answer for nor have I gotten a chance to test for myself to answer it.

When you use the "Wipe Data" command in ClockworkMod Recovery, does it also format the SD card?
No, it does not format the SD card.  It only wipes all internal memory on the phone.  It is recommended you do this every time you switch to a new CustomRom, or if the current CustomRom is giving you problems (typically after upgrading the CustomRom).