Should you encrypt your emails, and if so, how?

I asked this question a few months ago, and got a mixture of answers. In view of all we now know about the Bush administration spying on the Internet, phone calls, and more, I thought I'd ask again.

1. Is it wise to encrypt your email?

Keep in mind, I'm talking about keeping out the government, not just random kids playing games. But also, is it just wise for everyone, even if you're not worried about the government?

2. Will encrypting your email make things worse?

In other words, now your email will look suspicious and will get the attention of the bad guys in the Bush administration? Then again, if they have to unencrypt every single email I send, I imagine that would be a pain - or no? Once they unencrypt one, have they figured out the key to all of them?

3. What is the best email encryption software out there? I hear it's PGP, but then I hear lots of folks complaining about PGP, especially the price, which seems pretty absurdly steep. I can't believe there's nothing open source out there that works well?

4. Does it matter if you're on a Mac or PC, in terms of which sofware you'd want?

Are there any other questions I'm missing here?

I just think that in today's day and age, we need to be careful. Richard Nixon spied on his political enemies. Why should we believe George Bush to be any different?