Clipboard manager for pasting multiple items at once?
My favourite swiss army knife for OS X, LaunchBar, has clipboard history and management. In addition to being able to access historical, clipped information it can also do clip-merge. A quick double press of Cmd-C will merge the currently selected contents in to the current top-of-the-heap clipboard object for you, allowing you to paste them as one object with a single Cmd-V.

You can merge multiple items in the clipboard history by selecting the first one and doing Cmd-C and then selecting additional items and doing the quick, double press of Cmd-C. They'll all get merged in to the top item as expected.