Can you save a document in Pages and then upload it to a website?

You can use iWork.com to transfer files from your iPad to use elsewhere. You must initially start using iWork.com from Pages on the Mac, but after that it is a breeze to move docs back and forth.

Ps - it is free, but in beta phase right now, so not sure if it will stay free.

"specific site" - can you tell us what this is? Is it your own site? If so, you could use an FTP app on the iPad like +FTP to Go+ to upload to your own website via FTP, but you'd first have to send the file to the app's filespace, and I think the only way to do that would be via WiFi from your computer, so you'd probably have to e-mail it to yourself on a Mac/PC first.

Alternatively, since Pages can e-mail a Pages doc to an e-mail address; some websites let you upload by sending attachments to a special e-mail address, I guess you could do it that way...?

Right now Pages will only directly upload to iwork.com.

The simple answer is no. You cannot upload directly to a web site from any iPad (or iPhone) application that I know of. Nor can you download from one using Safari. Apple seriously restricts the way that you can put stuff on the iPad. It also restricts how you get stuff off. There are lots of ways to get things to your main computer after which you can do whatever you want with it. But you can't do it directly from the iPad except to email it to yourself. There's no way to "browse" the iPad file structure, without a serious hack, that is. Apple never allows the iPad to appear as another hard drive. 