Corfu was beautiful. I was very pleasantly surprised with how varied the island's topography was. They had lovely beaches (we went to Dassia beach, about 30 euros for a taxi and 6 euros for 2 lounge chairs and an umbrella) and then went to the old town area (another 30 euros for cab fare). The old town area is really neat and you can see the influences from the different groups that had claim to the island over its history.
Our guide was excellent and extremely informative. Wear good comfortable shoes that you don't mind getting dirty for this excursion. Also make sure to take a water that they offer for the hike. It is quite a bit of exercise getting to the top. The swim in the hot springs was really neat, but kind of a let down as the water was not all that hot and the seas were very cold at that time. Our guide did give us some great advice about Fira though and we found the Sphinx restaurant as a result. Excellent food, decent price, and an absolutely breathtaking sunset view over the caldera.
Paradise beach. Be careful as the right side of the beach when looking at the ocean is the more liberal and european side of the beach. Not a bad thing, we just didn't expect it and were a bit surprised when we got there. The area is beautiful though and I would suggest just taking the bus to get out there as it is only 1 euro 50 cents to get there.
We had a great time in Katakolon. KATAKOLON EXPRESS. Use them. They have very reasonable rates, and are great tour guides for Olympia. Don't bother booking through the ship for them. Their rates are roughly a third of the cost of the same exact tour on the ship. They give a great history of the area and do a very good job of explaining the cross overs with today's society.
Mercouri Estates Winery. They have excellent wine and some of the best olive oil in all of the world. The winery has been in the same family's operation for over 150 years and Christos, who now runs the winery with his brother, is a delightful person to get to meet and talk to a bit. I would highly suggest checking them out if you have the opportunity.