I posted about this on the KDE community a couple of weeks ago, but Dolphin (their file manager) has a nice trick for archives (zips, tar's, etc) - in the extract menu, there's an "Extract, Autodetect Subfolder" button which will:

• If the archive has an inner subfolder (and just that), it will extract this as expected
• If the archive doesn't have an inner subfolder, and all the files are at the root level, it will create a new folder for you and extract the files there

This way, you don't end up with files splattered all over say, your downloads folder. Easily one of my favorite features, and is something I wish every File Manager had. It feels like someone had the same pain that I do (and I'm sure plenty others) of extracting something, and regretting it - but then they went as far as to fix the problem for everyone and implemented a feature for it (I'd love to have the knowledge to contribute to KDE someday)!