Using my monitor for things other than my pc

i need a new computer monitor and i was looking at the dell E207WFP 20-inch Widescreen. if this isnt a good one for gaming, let me know. if its not then i need a monitor for around $250 for gaming. but my main question is how can i use my monitor for video games? like can i hook up my PS2 and XBOX 360 to it? is there a way that i can have my monitor hooked to the pc, PS2, and xbox at the same time? please let me know