Got 6 egg whites left over...

[bushymcbush]

... but have some shop bought meringue nests already. What else can I do with egg whites?

Well, you could make some meringue skulls and bones and serve them with a raspberry blood dipping sauce......so much more interesting than nests at Halloween !!! :)

or an egg white omelette :(

Marshmellow?

Meringues (I know you have some)

Macaroons