If you'd asked us a few months ago whether we thought there was room for two Youtube-for-documents style sites, we probably would have laughed. But then Scribd came along and showed that people really are interested in perusing interesting documents online and embedding them in blogs and other websites. And then Docstoc decided to tease us with a similar site geared more toward professionals.

While you can find pretty much any sort of document at Scribd, Docstoc has a focus on documents that can help with work. For example, users have uploaded forms for calendars, budgets, leases, invoices, and tax preparation.

We first got a sneak peek at Docstoc a few months back. But now that we've had a chance to peruse the site ourselves, we have to say, it's incredibly useful for anyone who needs a ready made form or two. Need to send an invoice for work you've performed, but don't have a template handy? Docstoc users have already uploaded dozens.

There's also a social aspect to the site. Users can create profiles and leave comments on documents uploaded by others. You can browse through the most popular documents overall or within various subcategories.

Docstoc is still in private beta, but we've got a few invitations to give away to the first 5 people who respond to this post. The invites are time sensitive so you'll have to respond and sign up today.

Update: Congratulations to our 5 quickest commentors! We're all out of invitations. But stay tuned, we'll be giving away invitations to a few more cool services in the coming days.