Turnaround time on email messages is usually under 48 hours, if I'm not drowning in mail at the time. If I am drowning in mail at the time (an increasingly common situation in the last few years), it'll definitely take longer to get back to you. Turnaround time on US Mail is approaching five years in many cases. So, if you have the choice, send email. If you must use US Mail, including a self addressed stamped envelope just might help to speed up the process.
...and please send a postcard. (See the Copyright Notice.)
(Of course, if you use this product and happen to work for Apple Computer, feel free to convince Apple to contribute a fast Macintosh computer system of some sort as a way of finally showing some support for this development effort. ...Not that I'm holding my breath, of course.)