How many audio inputs do I need?

[lostinthecity]

I'm looking to buy either a 2.1 system or soundbar, but the models I'm considering don't seem to have enough inputs to connect all the devices I'd want to run through it.

I'd like enough inputs to support the following devices:

• Sony KDL-40S2010 TV
• PlayStation 2
• Original XBox (used for XBox Media Centre)
• XBox 360
• Wii
• Squeezebox

Do I need one set of inputs per device, or is there any way I can reduce the audio inputs required (for example, is connecting some of the devices to the TV then running the TV's audio out through the system an option?). If the former, then what combination of audio inputs would best support the above?

Thanks in advance for any advice!