It used to be good, but then the new walkways/greenery totally fangled it all up. There is some parking in the back by Stevenson Field, but I don't know if that'll be checked for media. It is during lacrosse at least.
Best bet is to park up the street past MOses Brown and walk up. It's not bad even if it's cold. I've also shot for parking somewhere near the green and walked through Brown's campus, which is worth the hoof for its scenery. Unless it's freezing out.
The lot on the corner of Brook and Lloyd usually has some spots open. It's open to the public after 6 (it's a Brown faculty/staff lot during the day).