Lets say I did a check out, edited some stuff and realized I want to re-download the repository code and overwrite my local changes without commiting them.
I downloaded
From the Explorer context menu, TortoiseSVN, Revert (you may have moved some common commands up from the Tortoise sub-menu to the main context menu).
However, before reverting, I would do a diff (context menu, TortoiseSVN, Diff with previous version) to be certain that you are only throwing away what you think you're throwing away.
It is very easy to only think of the most recent changes and forget that you haven't committed something you want to keep.