Having just battled with my Droid to get a cert installed, I looked for a thread where I could share this finding. You will quickly learn that Android requires the cert in PKCS12 format, aka a .p12 file extension to "Install from SD Card". Have fun tooling around the web on how to convert a .pem file to a .p12 file. I found the command line windows based OpenSSL port to (a) work and (b) have the necessary support web articles to guide me through. All that said, I did learn that the .p12 must be in the root directory of your SD card, it will not find it in sub-directories. That's all, didn't see that comment anywhere else, so I wanted to get it posted.