I want to be able to position a chunk of text (which could be anything, could have \includegraphics, and could be on multiple lines) at the center of a page horizontally. However, I want to be able to customize its vertical position, say 4 inches from the top.
This chunk should be independent of the document's normal contents. So it should affect anything else on the page.
Is this possible?

\vspace{}? – Thanos Oct 07 '12 at 18:39textpos,background,eso-picortikzwould be necessary to place stuff on the page and not affect everything else. – Werner Oct 07 '12 at 18:50\vspace{}command creates a vertical space on the exact position(and only) you'd like. Try it and see if it will ruin the rest of the document. – Thanos Oct 07 '12 at 18:51