I have a Raspberry Pi and an Arduino and even a Netduino and I've done a lot of stuff with them but still nothing that useful when it comes to real Home Automat

I have a Raspberry Pi and an Arduino and even a Netduino and I've done a lot of stuff with them but still nothing that useful when it comes to real Home Automation. For example I'd love to open up the garage door from my phone, switch on the heating from work and so on... but I wonder what should I start from in order to get this running at home and should I go for it on my own in a DIY way or just go and see if I can buy something that is already in the market? I really don't wont to spend my nights in compiling low level C/C++ for arm microcontrollers... You've been working on your Arduino system for an year... why do you think it takes so much time? What does it do?