[Mongoose]

And the N looks like an R due to a lighter patch of nebula in front of it, and it'd be easy to mistake the G for a C.

[Qent]

Why not use re-captchas? That way they can prove they're human and feel good about themselves while doing it.

The "tried to join 20 times" has me suspicious though. Isn't there a refresh button that gives a new image? EDIT: Nope, so I'm now suggesting one.

[Fury]

Why not use re-captchas?

reCaptcha was used with SMF 1.1. Figure out yourself how effective it was.

[Androgeos Exeunt]

I don't remember needing to enter a captcha when I signed up three years ago.

A refresh button would be good, but stick to names with less ambiguity, like the GTCv Actium, perhaps.

[TopAce]

I say trim the number of pics, keeping the ones that are easily readable. That Aquitaine pic is bad for this purpose. Not only is A-q-u-i-t-a-i-n-e relatively hard to spell, there's that nebula.

[NGTM-1R]

Another one just got through.