If you want to come from Athens to Skopelos you can fly with Olympic to Skiathos. 
Here are some info I found on the net the 20th of May 2007:

FARE

One way fare from Athens to Skiathos is € 65,32 (about £44 or $87).

ON LINE TIMETABLE SEARCH

For on line / real time flight schedules click here.

ON LINE RESERVATIONS

Make your reservation on line and have your ticket delivered free of charge in your country. There are Olympic Airways Offices in more than 100 cities in various countries in the world. For an online time table search, please visit their web site at: www.olympic-airways.com

OLYMPIC AIRWAYS ON SKIATHOS

FOR TICKETS AND INFORMATION phone: 0030 24270 22229

FOR BOOKINGS  phone: 0030 24270 22200

DIRECTOR  phone: 0030 24270 22948

SKIATHOS AIRPORT  phone: 0030 24270 22049

OLYMPIC CATERING  phone: 0030 24270 24190

Send me an e-mail 
- keep in touch!