If you retained world-wide ebook rights, then self publishing through MobiPocket would be a good option, see
Publishing as a writer. Since MobiPocket is a wholesaler, this potentially makes your ebooks available on many sites selling MobiPocket ebooks. Note that the Addendum to the
Mobipocket eBookBase™ Publisher Agreement gives Amazon the right to also sell the ebooks for the Kindle. Amazon has been exercising this right for ebooks written in English, but I don't know if they routinely do so for ebooks in other languages.