Yes Groudle is lovely, but then so are most of the glens. Ballaglass is another one well worth a visit.
Whereabouts are you staying, and are you bringing your own transport?
What sort of things do you like to take photos of? There are too many things to list on here, have a look through some of the Isle of Man groups on flickr...
We're a friendly enough bunch!
Fingers crossed you get some nice weather