It’s a good bet that most geeks have a gmail account. I use mine mostly for mailing lists but many use it as their main email account and consequently are apt to have sensitive data in their saved emails. If this describes you and the recent NSA revelations make you uncomfortable, Etherael has a solution for you.
Phoneme is a small python app that retrieves your emails, encrypts them with your public PGP key, sends the encrypted emails back to gmail, and deletes the original unencrypted copies. Obviously this doesn’t solve all your security problems but it does take care of that large cache of emails sitting on Google servers. If your account is compromised there’s nothing of value for the attacker. If some government demands your material, there’s nothing of value for them to see.
This is a nice little hack and may help round out your privacy toolkit. Be sure to read the part in the README about emptying your trash folder after running the app.