Hello Tim!
I was about to email u for more details, but im not sure ure email address is still valid, cos mine isn't anymore. My new address is .eliasmelissas04@yahoo.com, u can email me to arrange things if u like, im especially interested in that historical lectures stuff, would be great to have someone else with me doing that, while hanging out in the city
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In the meantime, i will try to give u guys some links about hotels in athens: http://http://www.greekhotel.com/athens/
http://www.bookings.gr/city/gr/athens.en.html?aid=303626;label=athens-gr
The second link, aslo has a google earth map with all hotels. Bare in mind that hotels around the festival area (such regions are Vouliagmeni, Voula, Glyfada, Kalamaki or Alimos, Elliniko, Argyroupoli) are usually cheaper than the ones in the centre of the city, but i wouldnt rule out the centre or other areas so easilly, since, as ure saying, ure gonna stay for a couple of days, and there are gonna be ppl there having cars, who also like getting around 
As for how to get to/from the airport, i will give full details as long as u have decided where to stay, because it will mostly depend on that.
I will be away for a couple of days, i will reply to u and everybody else interested on tuesday or friday !