<p>Is there an easy way to find the storage card's path on a Windows Mobile device
when there is a storage card and a bluetooth ftp connection?</p>

On Windows CE 5 (which is the base for Windows Mobile 6) the storage cards get mounted at the root file system as "Storage Card\", "Storage Card2\", etc.
To find out if it's mounted call GetFileAttributes (or the remote version CeGetFileAttributes I believe) passing in the full path ("\Storage Card\"). If it returns INVALID_FILE_ATTRIBUTES then it's not mounted, otherwise check to make sure it's a directory before returning true.