Homemade mayo will keep through the expiration date of the eggs. I can personally attest to this. I buy the freshest eggs possible when I'm going to make mayo. The flavor is no different at the end of its "life" than on the first day.

I've made this BBQ sauce a few times. It keeps pretty well in a glass jar in the fridge for a couple of weeks:

http://civilizedcavemancooking.com/condimentssauces/beasty-bbq-sauce/

(I've started doctoring it up a bit. Once I make a recipe once or twice and know it's one I like, I tinker with it and make it more my own. It's great with ground cumin and a tiny bit of ground cloves added. Never tried with the pineapple like the author suggests, though. I have, however, used canned tomatoes - Muir Glen fire-roasted. Soooo good!)

I think any homemade vinaigrette would keep in the fridge. The oil might separate (and solidify if you use a good olive oil) but it'll mix right back in if you let it sit out for a bit and then shake it up. Don't have any recipes. I usually just wing it: EVOO, fresh-squeezed lemon juice or other citrus, some ACV, a tiny bit of dijon mustard or raw egg yolk to help emulsify (although not required), salt & pepper. Put it in an 8oz Ball jar with the lid on tight and shake away.

I can teach you something from my country - it is a very special sauce that people usually eat with meat or salt pork when consuming alcohol.

Ingredients:

horseradish root

tomatoes

garlic

salt (to your taste, I do not use much)

Any proportions. If you add more tomatoes, it is going to be more mild. If you add more garlic, it is going to be more... garlicky. If you add more horseradish... it is going to be very very hot and spicy.

Blend peeled and cut into pieces horseradish root in a blender. Add garlic. Blend. Add tomatoes and salt. Blend again. Keep refrigerated in a tightly closed jar.

health-bent (http://www.health-bent.com/category/sauces) has quite a few paleo sauces, typically really easy to make. I made the chili oil and liked it a lot. Put it on everything from scallops to asparagus.

I make mustard myself, that keeps fresh for several months in a bell jar in the fridge. I am always tweaking the basic recipe until I find my favorite one, but I always do brown and yellow seeds, next time I might try to leave the brown whole and ferment and ground the yellow, we'll see. Here's a basic recipe link text

Now that cucumbers are coming in season I also wanted to try some home-made relish. Mayo I don't like so I'll never try.

Whey-fermented mayo will keep for weeks instead of the non-fermented home-made mayo that only keeps for 2-3 days. Google for the recipe.