If you ever have the need to hide text from web crawling bots such as email gathering spam bots or search engine spiders, then putting your text in an image and posting the image is an effective method. Of course, this can be cumbersome for obvious reasons. Instead of doing this manually, check out Hide Text.
Hidetext.net lets you convert text to an image. This means you can hide passwords, personal messages, pieces of code, or any kind of private information on forums, blogposts, emails, irc, msn-aim chats, [etc]
Usage is simple, just type in your text and click a button to generate an image. Additionally, you can use their email specific tool to create a multi-color, multi-font image of your email which essentially makes it readable only to humans.
A great article which covers this tool is available here. This is definitely worth a bookmark if you do a lot of posting on web sites or want to publish your email on your web site.