If the petals are dried, you could powder them in batches in a blade coffee maker until you have 2.5 ox (70 grams powder) and make this popular cake: http://buttersugarflowers.com/2016/01/31/buttermilk-hibiscus-cake/

Karkaday (as the hibiscus infusion is called in Egyptian Arabic) is a very popular drink in Egypt, with or without sugar, served both hot and cold.

Like the ones they sell at Trader Joe's?

I would play around with strawberry-hibiscus or cranberry-hibiscus scones. Or jam, simple syrup, tea, ice cream, cake, cocktails.

Merrill wrote about the hibiscus in syrup last summer, and includes a nice margarita recipe: http://tmagazine.blogs.nytimes.com/2010/06/28/the-new-staples-oat-groats-hibiscus-flowers-nutmeg-and-mace/

Take a bunch of it and heat it in a simple syrup (sugar/water) in a pan. Let it cool, strain it, and then use it in cocktails or toss with fresh fruit and mint for a simple dessert.

hibiscus-sorbet http://www.chefeddy.com/2010/09/hibiscus-sorbet/

Make it into a kambucha!

Tea?