In my experience, trying to foil spam harvester bots is about as effective as trying to repel mosquitos with deoderant. The fact is, if you have an active internet presence, you're going to get spam.
Every time you build a bigger mousetrap, somebody builds a bigger mouse. I've seen people out there go so far as to use something like "winterchase [at] hotmail [dot] com", which frankly I think is just getting obsessive. I mean sure, you might get one or two less spams a day by doing that, but how many legitimate and important business related emails are you missing in the process too?
The internet is becoming more and more automated each day... your site visitors want convenience, ease of use, automation, efficiency. If you're going to force them to open an email window, translate the contact details you've offered into an actual address, and manually type your email address into their email client, you'll find a lot of people just keep moving. The average internet user has an attention span of about 12 seconds - if you haven't got them by then, you've lost them forever.
Personally, I always use web based contact forms as has already been suggested here - not only is it more secure for your email address, but it ends up actually being even more automated and efficient than a hyperlink to your email address is, so it's a win-win. Failing that though, I say just forget about it - if you spend time in the sun, you're going to get a tan, and if you spend time on the internet, you're going to get a spam. It's just a fact of life. There are plenty of great spam filtering programs out there these days - don't risk missing out on legitimate real email just to try and get a few less spams.