Google announced an interesting development for Google Docs last week. They have issued an update to include PDF support, adding one of the most popular online documentation and form format to their free suite.
The addition at this point does not include editing or saving PDFs, only the ability to read PDFs and paste into fields. However, it's a jump from having no PDF support at all. The Google Docs team claims that the inclusion of PDF support was prompted by Docs users.
Some very Google-esque features are currently missing from the PDF support function, including the ability to search through documents (that I could find) and a lack of mobile support. However, the feature is only a few days old - and will likely be even more smoothly integrated into the suite soon. Google Docs as a whole does suffer from a bit of a feature-lock, in that suites like Microsoft Office and OpenOffice have a veritable horde of functions at their disposal. Still, if you like the idea of office document collaboration, it's a fantastic tool.