After significant other declared a sudden love of semi-dried tomatoes (hmm.. doesn't like fresh, doesn't like dried, but semi apparently does the trick...) I tried making some at home. I also had a glut of pineapples, so I sliced some thinly and put them in with the tomatoes (making sure the juices didn't mix). It was a low oven for I don't know how long. I sprayed the pan with a bit of oil to prevent sticking. I didn't add anything, but they were sweet, slightly chewy but still juicy. Took the edge off the acidity as well. Great snack, and I would suspect would make a good garnish for some posh dessert. I'm warning you, now, though: these are HIGHLY addictive. Was tempted to dip in dark chocolate (actually I think they'd take better to a light drizzle), but I couldn't stop myself from eating them before I could get the chocolate. I couldn't tell you how to store them because we didn't quite get that far.
I'd be interested in hearing about anyone else's forays into semi-dried fruits, and particularly how you stored them (and for how long). Perhaps the poster with the glut of plums may want to experiment? (although full drying is probably best in their case...)