FillAnyPDF is a free online, SSL encrypted PDF form editor that allows you to upload your PDF form so that others can fill it out and even sign it online. While it's marketed as a replacement option to the fax, the appeal and practical uses are probably broader than that. Small business, non profits and volunteer groups who have limited resources and lack techie know-how now have an easy way to collect information online for projects as they come up.
FillAnyPDF offers the ability to send forms via an email link, HTML link, or to embed the entire form in HTML on your website. As the forms are filled out, the data collected can then be emailed to you or you can access the data when you log in. Users don't have to register to fill out the form which is another nice feature. The interface is simple and while it is ad supported, the ads are non obstructive. You can easily search your forms using tags.
Still in beta, FillAnyPDF is developing upcoming features such as hosting FillAnyPDF software on enterprise users' servers, group sharing and collaboration, etc. Trusting an unproven start up with financial information or personal information like social security numbers isn't something I would be comfortable with, but for basic information collection, I think FillAnyPDF is a strong option to consider.