Registration captcha is a train wreck

[klosure]

Took me 5 attemps to manage to read the letters.
And that was only registration. Now I have to do that each time I post   .
Consider changing your captcha generator.

[psztorc]

You only have to do the captcha for (something like) your first 7 posts.

Spam was getting through with an easier captcha, and I would prefer only to allow in users who actually care about what they have to say (enough to beat a few hard captchas) but I suppose I can make it slightly easier.