Well, as I've been relying on CCC for as long as I've known about it (way back in my G4 days), and (as far as I can recall) never did get round to donating, I'll be more than happy to shell out the £26 for a full licence. Interestingly, Bombich seem quite happy for users of OSX 10.7 and under to keep on using the 'free' version (v3.4.6) without forcing them into the commercial version (v3.5), they even offer the following advice:

Can I continue using the older version that is "donationware"?

Yes, absolutely. Note, however, that previous versions of CCC are not qualified against Mountain Lion. Choose "Update CCC..." from the Carbon Copy Cloner menu to see options for disabling the CCC software update checks.

and then slipped this little nugget in too (for the true cheapskates out there):

Please note that Carbon Copy Cloner has never been sold as part of a software or hardware bundle in the past. Also, note that simply clicking the "I paid" button (which would have suppressed the banners) is not the same thing as sending a donation to us. (my bold)

Having said that, as much as possible Shareware authors should be paid for their efforts in general, and when it's for something so damn useful then there's no excuse.

Vince