I'm looking for a method of controlling an arduino w/ ethernet shield by "sending" it a tweet. Essentially, I don't want to carry the keys for my apartment when I go for a run and want to tweet from my phone and have that active the buzzer in my apt. I don't want to use processing/python because I don't want to leave a computer running 24/7, where I'm willing to leave an arduino running full time.
I've been searching for a couple of hours and I can't find a good method of doing this.
Here's what I want to create: Phone > Twitter > Ethernet Shield/Arduino > XBee > Xbee > Buzzer
I may need to add in some segments in there to accomplish what I'm trying to do, but I'm looking for guidance. Can anyone either point me in the right direction or tell me why this isn't possible?