That is a great idea for a dinner party .. so easy to make them ahead and there's something really wonderful about getting your very own little pie. It's the same principle as the cupcake .. a beautiful small warm treat that's all for you, the whole thing.
I sent this link to my sister who is a very notmartha sort of person who had inexplicably not seen the site before. I believe she is whipping up some tiny pies as I type this. Alas she lives several hours away so the tiny pies will not be mine....
For a couple of Christmases now, I've had the tiny pies bookmarked, thinking I should make a freezer full of unbaked tiny pies, bag them, box them, and give them as Christmas gifts.
(There is nothing so lovely as an unbaked pie to keep in the freezer; when you want pie, you just pop in in a pan, then into the oven, where it perfumes the whole house as it bakes. Then --- hey! --- fresh pie!)
Not sure why I never have made them, except that I just know that I'll have the old familiar urge. The "how many can I fit in my mouth at once?" urge. And I'll bake 'em up and cram 'em in.
We always used to do this with pastry scraps left over from the big pies. It was also my chance to experiment with fillings when I was a kid. Hence, for example, the notorious and none-too-soon-repeated "raisin pie" incident.