I gave up on using my Pi as a VPN'd NAS, since the CPU is too slow to handle OpenVPN (see here [Low bandwidth internet over VPN](https://raspberrypi.stackexchange.com/questions/4640/low-bandwidth-internet-over-vpn)).

So I want to set it up to do (all of) the following:

1. Control a light switch
2. Switch my speaker system between either of two audio inputs (laptop or desktop)
3. Link to my Android phone through an app, allowing me to control the Pi to do (1) and (2) through my phone

I have a fair amount of programming expertise, but I'm pretty inexperienced when it comes to hardware/electronics, so I'd really appreciate some help -- specifically whether you think it's possible to build interfaces on the Pi that allow me to do the above.