Way back when, there used to be a little company called “Macromedia”. Some of you older heads might remember them. For a long time they were the big name in web development- until they were bought out by Adobe.
Macromedia had a great section on their website called the “Exchanges”. These were essentially forums where users could post scripts, plug-ins, actions etc. for every Macromedia product.
When Adobe took over Macromedia, they not only kept the Exchanges, but expanded them to cover many of Adobe’s products as well. If you have never been on the Exchanges, I would highly recommend it.
The Illustrator exchange has custom brush libraries, and all kinds of templates, as well a some useful plug-ins. The InDesign exchange has some really cool stuff, including scripts that will create editable calendars in InDesign.