If, for one reason or another, you don't have or don't want Microsoft Office installed, but you still need to view a doc, spreadsheet or presentation, the ThinkFree Online office crew have created a couple widgets (and even a Google module) to help ease your pain. I haven't been following ThinkFree's products very closely, but one of their services called the ThinkFree Viewer lets anyone publish a document online by linking to their web-based viewer - this removes a visitor's need to have one compatible app or another installed just to be able to view the file.
To make things even easier for those attachments you receive or the occasional document you simply have lying around, they have now released a new Dashboard widget and a Google module (for their Personalized Homepage), in addition to the Yahoo! Widget we blogged way back in May. These all work essentially the same way: drag and drop a compatible ThinkFree or Microsoft Office doc onto the widget, and it will upload the file to ThinkFree's temporary online viewer so you can crack it open with the least amount of hassle. Of course, there might be limitations to what their viewer can render, but this should make things a little easier for non-Office Office users out there.