Spam in Blogs - Is there a fix?

After dealing with 20-30 spam posts a day, the search was on for something different.  The positive of allowing posts is the ability to have a mini-community discussion.  When dealing with 20-30 bad/spam posts a day then takes away from the functionality.  These are some of the solutions that I have looked into.

Twitter
Pros - A number of the spam is dealt with by Twitter, clean look with Twitter feel
Cons - A little consuming to get working on Mura, commenters have to have a Twitter account, have to stay up-to-date on twitter (constantly connected)

Facebook
Pros - Pretty easy to implement, looks good, nice format with pic person and text, shows real people
Cons - having to stay connected to Facebook, commenters have to have Facebook account

Other Software
Pros - Some are easy to install, some have good functionality
Cons - Some are difficult to install, still nothing is spam proof

So, nothing is perfect and I am still looking for the best solution.

Though I do like spending a little time and figuring out where the spammers are and redirecting them away from my site all together :)

So those that care, leave me a comment on what has worked the best for you.  Spammers, I ask that you go away, but I know you won't, so thanks for spending your life on my site!