We've been working on a project called "AxShare" for easily sharing Axure RP prototypes. It's a work in progress, but you can try it out at http://share.axure.com/.
Just upload an RP file, add an optional password, and AxShare will give you a link to the generated prototype that you can pass along.
The files are limited to 5MB right now and the link to each prototype is valid for 30 days. The email you'll receive after uploading will also give you the option to remove the prototype sooner. The uploaded RP file is deleted from the server at the same time as the generated prototype.
Please think of this as a test environment. We're hosting AxShare on Amazon Web Services which has very little downtime, but we will be testing new prototype features and there may be some unexpected downtime, changes to the prototype generation, and bugs.
As always, send any feedback and bug reports to support@axure.com.
