Set up a Google Docs spreadsheet. Put a stock symbol in A1, put
GoogleFinance(+A1) in cell B1 for the real time price of NYSE/NASDQ
stocks. Then put a formula in C1 to calculate Buy/Sell//Hold, then
color the background of Buy green, Sell Red and Hold no background
color.
Most major brokerage firms have Price alerts. Fidelity is one of the
best.
Rip