I’ve been pretty pleased so far with the popup window control from LivePipe. It plays nice with Prototype and is easy to style with regular CSS. We had considered using Prototype Window but I was put off that all their default styles looks like operating system windows and restyling their windows required a table and 9 images.
I’d recommend anyone looking for a popup window solution at least consider Livepipe. There are downsides however, chiefly that the project is pretty immature – technically I suppose this is an alpha release since Beta One is being worked on, so the community remains small. While there are some folks already submitting patches, progress on merging the patches is alarmingly slow, as one can see from their lighthouse page.
If you’re doing RESTful stuff in Rails however, you will need the contents of ticket #10 which modifies the popup window to accept an option to use different HTTP verbs.