You might have seen the ads about Cadalyst Online PlanRoom.
Cadalyst Online PlanRoom is a secure, Web-based project management system, featuring easy-to-use, time-saving tools to help you collaborate and streamline projects by centralizing plans, large-format drawings and specifications in one place.
It says "Click Here to Register for a FREE Account". Looks like a great deal, but if you read the fine print in Terms & Conditions you will notice that it says "for trial purposes only."
Another think in the FAQ that I reacted about was this:
Q. What types of files can I upload and view?
A. Image files such as TIFF and JPEG are the safest file types to use. Adobe PDF and Autodesk DWF formats are also supported but may take slightly longer to view. CAD files such as AutoCAD DWG and MicroStation DGN may also work, but are more complicated and can contain links to XREF (External Reference) files that will also need to be uploaded. Most PLT plot files also view, as do office documents such as Word, WordPerfect and Excel files.
Notice the text I made bold. I don't necessarily agree with that unless you have very low quality of your image files.