Sicily, of course. May is perfect---see for yourself:
http://www.slowphotos.com/photo/showgallery.php?cat=3828

I booked my Malta trip through
http://www.academictours.com.
I did flights only--no tour.
They do Sicily + Malta.

Tunisia is another option.

Since many flights go through London, I think your options are limitless.

Just noticed you said July--probably hot for Tunisia.

Definitely Sicily!

Thanks for your input. How will the crowds be in Sicily in July?

We realize it will be hot in Malta then (but the conference is scheduled so can't get out of that date) so we are toying with whether we want to stay in the south/heat or use the second week to take a hop out of London to cooler climes.

Any thoughts?

Sorry, I missed July. Too hot in Sicily. I suggest the Alps in July---perhaps the Italian Dolomites.

We are also going to a conference in Malta this May - we have been thinking about Sicily and your photographs (very beautiful) have confirmed it! We will have 4 to 5 days. Our plan would be to take the ferry from Malta when we arrive from the US (in spite of jetlag) -probably on a Sunday - stay for 4 nights-go back to Malta on Thursday afternoon and start working at the conference on Friday.

My husband is a professional photographer so although this part of the trip is holiday, taking photos is very important - so renting a car and touring on our own is always the best bet. Given our time and your photos, I am thinking Taormina, Siracusa/Ortega, Arigento ??? We don't like to stay at a different hotel every night if we can help it - maybe 2 nights one place, 2 another. Love to hear your suggestions - everyone's posts have already been extremely helpful.

I was researching about my upcoming trip to Malta the first week of September 2009 and noticed your post indicated you will be there next month (July). Please let me know how it is and where you ended up visiting, tours you took, etc as I am still trying to set things up for our trip. Also, I think you should take advantage of seeing Sicily since so close by and it won't be that much more unbearable than any other close destination in the middle of summer. Might as well take advantage of proximity - there are ferry boats to Sicily from Malta that operate daily. I will be doing it the other way around, staying in Italy and then flying into Malta.

Unfortunately we had to cancel this trip as my brother decided to get married one of the weekends we would be there and since the trip was centered around my mom's conference we couldn't persuade her to ditch the wedding. We are hoping to get there some time in the next few years though. I will be waiting to here how you enjoy it!

Sicily is a good choice, but you should carefully take a look at the Aeolian islands right above Sicily; Ischia- an Italian island with two really great spa parks, or up further north also in Italy is Elba with super clear water.... but I guess anywhere with good swimming and gelato would be paradise during hot July.