I'm looking for options at bulk, cheap extension of Arduino output count. For instance, to drive led arrays on moving parts, where wire count is at premium. Connecting shift registers in series seems like a good solution. It'd be great if those outputs would have power rating of Arduino pins. Also it'd be great to find one-chip solution for switching substantial loads at different voltage, say 4V@250mA or 12V@1A, though I imagine that definitely wouldn't be cheap.
Edit: in general it'd be great just to have chip names to Google for to get understanding of available variations