EVDO on iPad2
I have a Mi-Fi wireless router (Verizon). It works well. There are no apps that let you use the camera USB adapter for other than transferring photos. Other data transfer does not work. As for PCMCIA interface devices ... ipad2 does not have one nor interface with one.
Therefore, at this time your desire to use USB or PCMCIA interface connections is not possible.
You are forced to use WiFi and of course you must be within range of the sending device... so it doesn't give you cell phone connect anywhere.