LoopApps is a one stop shop for your PDF manipulation needs. There you can convert, combine and electronically sign documents.
We've covered some excellent web-based PDF tools before, including MergePDF, HTML to PDF Converter, and Free PDF to Word Converter, among others. LoopApps combines the functionality of a variety of previously covered tools into one tool.
You can convert multiple formats like TXT, RTF and DOC files into PDF files or pull directly from URLs you input. You can merge multiple files together in the order you want. Files can be electronically signed using the ESIGN service which is conveniently available without an account. Almost all of the functions are available without a login, but signing up for a basic account allows you to access more advanced features like the ability to shift the page order in your documents. If you have a favourite web-based tool for document conversion and manipulation, sound off in the comments below.