Wow... definitely packing things in

Delphi - Day trips there are certainly possible and there are plenty of tour operators that can be booked locally which will take you there. It's about 2.5 hours by coach, I guess. I've only been there in winter (and it's quite a sight in the snow) so I can't comment on whether its worth the trip bearing in mind how crowded the place will be.

Acropolis - you've got to really... Check the opening times, though, as you've not got a great deal of flexibility in your itinerary.

Nat. Arch. Museum - Depends on how interested you are. I found the museum rather staid and uninteresting - though it's hard not to be impressed with the quantity and quality of the artefacts. This is a collection that desperately needs a better home. (I've not visited since the pre-Olympic rennovations so it may well be better now...)

I also recommend visiting Lycabettus hill in the centre of Athens - from there the views of the city are fantastic (if that's your sort of thing). There's an underground funicular railway to the top but by the time you've walked up to the bottom station (and found it!) you might as well continue to the summit on foot.

Knossos - Not been to Crete so can't comment, sorry.

Santorini - ^ You may need to add to your itinerary: Day -1, arrange new mortgage to pay for cocktails on Santorini

HTH,


m.