Olive oil injection - the hot and not so hot of:
Olive oil injecting a turkey for flavour and moisture is hot. I can see myself doing this with a chicken and mixed EVOO, sesame oil, and orange juice, or a nice piece of roast lamb using olive oil blended with herbs.
Note that you can get the same effect without looking like a hypodermic-seeking druggie by taking your carving or roasting fork and perforating the roast before rubbing the oil marinade in, and this method has the advantage that it tenderises the roast, allows you to use granular stuff in the oil, and also you can insert things like slivers of garlic or herbs in the holes.
You just have to make sure you really perforate the roast with dozens of holes, as deep as you can get. And leave it laying on the treated side for a few minutes to allow gravity to take your marinade deep into the meat.
Self-injecting is not hot...