Idea is about allowing to create spreadsheet (not full document, but single page), with will be connected with one (will be like part of another spreadsheet) and be floating/moveable. Why? Sometimes, I need to do fast and (maybe) temporary calculations, such like costs for last two months. Normally, I will put into page cell, which will summarize cost for single year. But… maybe I will need to fast calculate cost of part of year? So I will open float page, move it around parent page and type (in one cell) =SUM(!SPREADSHEET_PARENT.A1:!SPREADSHEET_PARENT.A2). I can save this page in next steep as separate spreadsheet or document (without foreign formulas - it will be calculated and results will be put into cells).
What do you think?