There's now a Paypal button at the top of my main ACT website. Simply put, random people have asked about donating and there was no avenue. So I'm using a Paypal "proxy" to accomplish this. As its a proxy, I won't know about transactions immediately, but don't worry, its going to the right place.
I have absolutely no plans to make ACT a product that you must pay to use, ever. Use of the donation button is completely optional and will not affect your status as a user of ACT.