How much space does the blockchain take up per day and per hour when running bitcoinQT on my computer? the blockchain is about 20GB today, but i was wondering how much space does it take up each day if i were to leave bitcoinqt on regularly? also by hour? reason why im asking is im thinking about just putting the blockchain in my cloud drive (bitcasa.com) as my laptop has only so much space. if its not too much space that means it wont be a bandwidth hog when its uploading it to cloud drive after it downloads it.
The blockchain size growth is kind of approximately linear at this time (although I wouldn't expect it to continue linearly). See the nice graph at https://blockchain.info/charts/blocks-size and particularly check the "All Time" scale option.

Over the past year, the blockchain size has grown by approximately 10 GB. On average, that would be around 27 MB per day, or 1.1 MB per hour.