A new blog hopes to highlight local music. D.C. MP3, which launched this week, intendes to select one song each week from the Washington Post’s MP3 website, which provides “Self-publishing by and for the Metro region’s music community.” The site make downloading the MP3s simple – no registration, just clicking a legal agreement not to sell the music. D.C. MP3’s first selection is I IN TIME’s “Sunset Strip,” a well-executed if straight-forward rock number. Never…