YemuZip is a simple, free utility with a single purpose: to help you easily create Mac- and PC-friendly ZIP files with just a quick drag and drop. The Mac OS already includes ZIP-compression functionality (which you can access through contextual menus), but YemuZip add some extras--most importantly, the option to choose between Mac-specific and PC-compatible formats, removing the Mac metadata in the resource fork that can otherwise make ZIP files made on a Mac unreadable on PCs.
You just drag files into YemuZip's main window, or onto the YemuZip Dock icon, and the app creates a zipped archive in a destination you specify (or even directly into a Mail attachment). You can set the app to automatically quit after compression, and for PC-compatible files, you can also adjust compression performance and speed. If you regularly create ZIP files (especially that you share with PC users), YemuZip should be an obvious addition to your arsenal.