From the half-glass department: check this map of licensed LPFM station coverage in the continental United States (click for larger versions):
Now, a map of licensed FM translator station coverage:
Although expansion of the LPFM service has been stunted since 2001 (no new applications for LPFM stations have been allowed since then), the number of translator stations continues to grow. Lest we forget that in 2003, one firm operating under two guises applied for four times as many translator stations as there are licensed LPFMs in the United States.
Images above are rasterized from FCC PDF documents available here. You can find similar maps for Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The FCC’s web site seems full of little surprises like these.