From the FAQ:
figshare is the first online repository for storing and sharing all of your preliminary findings in the form of individual figures, datasets, media or filesets. Post preprint figures on figshare to claim priority and receive feedback on your findings prior to formal publication.
You could use use it to upload non-peer-reviewed tech reports, posters, talks, figures, etc. The site offers unlimited space for public data and 1GB storage for private data. Pretty sweet.