Shameless plug: Pacifist can let you selectively extract files from .zip archives too, and it has a nice little twist: it can open zip archives over the network. If you open Pacifist, click the "Open URL..." button, and enter a HTTP URL to a .zip archive, it will open it remotely over the network, let you selectively extract files from the archive, and only download what's necessary to extract that one file. So if you want to extract a 10 KB text file from a 50 MB zip file, you don't have to wait for the whole 50 MB zip file to download.
Of course, Pacifist is an extractor, and it's not for creating archives, so if the latter is what you want, you'd be better off with BetterZip.