If you're ravenous and unable to find real food, this nutritious emergency meal can be rustled up in even the most ill-stocked convenience store: yogurt, peanuts, and orange juice.
If you must eat fast food, order fries. At least they're a vegetable.
Every mediocre bakery has one decent thing, and you can find it if you look hard enough (it's never colorful, it's never a big cookie, and it's never something that requires butter to be good--e.g. croissants).
At really awful big catered functions (redundant?), stay by the meat slicing station. At least it's not exorbitantly greasy and salty, and there's probably nothing evil hidden in it (though smell the meat before you ingest to make sure it's reasonably fresh).
Avoid like the plague any dessert in a kosher place that requires dairy to be good but has to fake it 'cuz it follows a meat-based dinner (which means: go for fruit and nuts).
Per another thread...if there's absolutely nothing else, consider hotel restaurants (but....shudder)
Coors Lite is totally lousy beer, but it's fairly inert...at least doesn't have bad flavors like Bud, Miller, Schlitz, etc. But remember that bourbon is always a possibility.
Also, don't forget our superb "What Should I Eat at TGIF's?" thread for great tips on surviving chain restaurants. Link below.