CAPTCHAs: possible to replace Google's ReCaptchas?

Hi Wiki team,

I’ve just stumbled into a long, long series of perfectly indecipherable CAPTCHAs again when trying to submit a wiki paragraph containing URLs. I remember that they used to be fairly easy, but this is not the case anymore IMHO. Is it possible to replace them with something else?

I had the same problem with another use of recaptca the days before. See for an simular discussion.