So, if you have 3 tabs open, each with a bib record, and choose one of the Tile MARC actions, you'd get a 4th tab containing all of those bib records? For code leverage, you may want to look at the Merge action in the Record Buckets interface. It lays records out side by side and allows you to edit them in addition to merging them (you can switch between the MARC View, the MARC Editor, and Holdings Maintenance for each bib thus presented).
Something I played with in the past was a framework for showing multiple active tabs in a split window. That might be another route to think about. There are Firefox plugins that do similar things. -- Jason
