It's hard to add dry spice mix to coffee and really hard to add pumpkin to coffee and not have a scary mess, but look for pumpkin spice flavored coffee beans, or maybe some of those other foo-foo flavors. Cost Plus World Market, if you have them in your area, has flavors like egg nog, chocolate peppermint, and marzipan (almond) coffee beans.

To make a pumpkin spice latte:

Pumpkin Spice Coffee beans
Milk
Vanilla Syrup
Whipped Cream
Cinnamon
Nutmeg

Brew your coffee and steam your milk. If I want foamy milk, I put it in a large Pyrex cup and microwave it until hot, then take put a whisk into the hot milk and spin the handle in the palms of my hands to get some real action going. This makes a pretty good foam, or you can use an espresso machine to steam your milk if you have one, but you don't need foam if you are going to have whipped cream. Put the vanilla syrup in the bottom of the serving cup. Add the steamed milk, maybe 1/2 of the cup or less, then the hot coffee. Top with whipped cream squirted on from a can so you get those swirly lines in it and sprinkle on the cinnamon and nutmeg.

You can buy vanilla syrup at the supermarket or the specialty stores, but here is a recipe to make your own, and it doesn't have a bunch of strange additional ingredients.

1 Cup Water
1 1/3 Cups White Granulated Sugar
1 Tablespoon Pure Vanilla Extract
Place a saucepan on the stove on high heat and immediately add water and sugar. Whisk together until the white sugar dissolves and bring to a boil. Once the mixture has reached a boil turn down to a medium heat and continue to stir for a couple of minutes until smooth. Remove from heat and add vanilla. Let the mixture cool and transfer into a container with lid for storage.