Not a big watermelon fan here, but I picked up a seedless one at Costco Friday and it's been chilling in the fridge since then. The salad and cheese treatment sounds like it would perk up what is generally a too bland food, so I may give that a try. No fresh basil in the garden today but I could always pick some up at the local hacienda. I do have fresh oregano but that might be overkill.
I'd also probably try substituting Parmesan for the feta, or maybe some swiss. And I have some red onions so they could sub for the chives.
Another idea for salads: slice up some sweet Fuyu persimmon and use it as a tomato substitute. Surprisingly good.