Since restaurants are private property, legality isn't the issue. The manager is. I often park in the triangular patches, as long as I don't block the person in the legitimate spot. I also look for sidewalk nooks, such as along the building where there's a jog in the wall. You can often find dead space that no one will miss. Be aware that you might draw unwanted attention to your bike by doing this.
Another option is to carry a sidestand plate with you and just park on the asphalt in a regular spot. I riveted 4 compact discs (AOL promotions!) together and keep it in my tank bag. Some use steel coasters. As last resort, I've used a store flyer folded several times.
BTW... that's a ... lot of ... periods.
