QUOTE(bernoulli @ Mar 26 2007, 08:14 PM)

One thing I can be absolutely sure of, is that ATC does NOT want the pilot to take it upon one's self to take matters into their own hands by "helping" ATC by fiddling around with different indicated headings to obtain a track angle down the runway centerline, or assigned heading.
Just keep it simple and fly the assigned INDICATED heading. ATC will work out the rest.
Been away for a while, but I'll give this one a go..
Most of the time when you see an airport departing and arriving on parallel runways you're looking at a busy class b or c airport. Most b and c airports have radar towers which put basically means that they can give you headings and such. As a side note, the "non-radar" towers can still issue headings upon departure, but they have been worked out beforehand to provide adequate separation prior to the radar facility assuming control.
Now most class b airports departing multiple runways have standard instrument departures which dictate headings and altitudes to guarantee departure separation. The towers that do not though will certainly take wind into account (remember of course that the wind will be generally blowing "down the runway" so it's slightly easier). What I find interesting is that most modern jets take into effect the wind and will fly the "track" heading rather than the "magnetic" heading so that they are flying the assigned magnetic heading corrected for wind while most G/A airplanes fly straight magnetic headings and are blown around by the wind. Now if you and I know that, you bet the controllers do

. In summary, fly the magnetic heading, and keep your eyes open.