OK Kurtz, we all get the idea that the "egos that be" prefer that Emergency (ER) Medicine be referred to as EM. Boy, that ONE letter makes a huge difference to some people (yes, these are probably the same people that won't let you use their notes if you miss a lecture)...
Anyway, Sandlot, I have posed this question in the past, and it seems that a good score to shoot for is around 220 for most programs. This won't get you in at the best programs, of course, but it will make you competitive overall (as far as your score is concerned). If you're a person truly interested in "EM" (and not someone applying into a couple other specialties), you'll likely fare well.
Keep in mind, the US-MD unmatch rate for "EM" was rather low for the 2002 match, at around 6.5%. I know that people sometimes rank more than one specialty, etc., but this is an overall indication that due to the number of programs, your chance of matching somewhere (if you don't care where you go) is relatively high regardless of your score when compared to specialties such as dermatology, ophthalmology, orthopedics, otolaryngology, plastics, neurological surgery, radiology, etc.
The number of spots is substantially greater than 1,100, I believe.
Cheers, Bigfrank
