Have finally got around to uploading both Torc and The Prospect of This City to both Kobo and Smashwords, which means that they're available for all e-readers and mobile devices. This means that those who prefer not to buy their books from Amazon can join in the fun too.
In future, if there's stuff that I self-publish, I won't do it exclusively through Amazon, but will release simultaneously across multiple retailers. At present, though, the paperback versions of both books are only available via Amazon. Am still investigating alternatives, though the economics of self-publishing on my modest scale don't lend themselves readily to anything but a print-on-demand option (which is what Amazon do).