POLL: HOU vs. PHI & LA vs. NY in Conference Semi's second legs: Who will advance?

Star-studded LA vs. NY and HOU vs. PHI both on tap tonight.

MLS Playoff Conference Semifinals continue tonight as we near the final four teams left standing in 2011.

First off, Philadelphia Union, down 2-1 on aggregate, travel to Houston to take on the Dynamo in the Eastern Conference Semifinal second leg (5:30pm PT, ESPN2). After experimenting with a new formation in Philadelphia, Peter Nowak's side will have to contend with a physical Houston team. Will Houston hang on to win and advance against Sporting KC or will the Union come back?

In Los Angeles, the stars will be out tonight as Thierry Henry and the Red Bulls travel west to take on the Galaxy (8pm PT, ESPN2). Tensions ran high in the first leg in New York which LA won 1-0. Rafael Maquez and Juninho both picked up red cards in that match for New York and Los Angeles respectively so will be out for this match. Can New York travel cross country to win or will David Beckham and Landon Donovan help close it out for the Galaxy?