"Donds" originated on Readers Recommend, a music blog on the website of the Guardian newspaper in the UK. It began its lexical life as a typo, posted on 13 May 2007 at 15:55 by "Ejaydee" of London, who mismanaged "seconds" (as in "I second the motion"), and wrote "Secdonds for the Sesame Street Theme Toon!!!!" This bounced back later as "sedonds", which was the accepted form for a few months--a joke mis-spelling along the lines of 'pwned'.
“Donds” first appeared when "BlimpyMcFlah" used an apostrophe to abbreviate in comment no. 657714 at 18 minutes past midnight on 24 August with "Immediate and massive 'donds....". By the following morning "donds" began to be used in its final form and meaning.
There have been some playful variants:
“dondage,” “dondarino”, the pseudo- Germanic “gedondheit”. But the default usage is “Donds to that.”
As of autumn 2009, "donds" remains a very common term on the Readers Recommend blog, but unfortunately it hasn't really spread beyond its place of origin.