At the end of the trading day, mm's usually inflate the ask. What I have found the last couple times was that I could place my sell orders gtc at 4x the ask. This way it helps a little bit. This is with Scottrade.
ST does allow you to to do that...from what I was told, you have to call ST to place the sell for you at that share price (cannot do it online at that price). The charge is $20.00 instead of the usual $7.00 (plus the 1/2% commission).