I downloaded the Jcalendar API and added it to my projects library and build path as usual but now I would also like to add it to the swing palette for more convenience. I know it's possible with netbeans and I'm pretty sure you can do it with Eclipse and WindowBuilder Pro also, I just can't find anywhere how to.
I actually figured the problem out myself. Just right-click on the swing palette, then choose Palette Manager and from there you can import jar files and add them to the palette!