I'm thankful for my most frequently used iPhone application - Notes! I write so much and so often that putting down my thoughts wouldn't be half as easy without it!.. I write at home when taking a shower, while eating my breakfast, in my bed at night, I write on my way to work and at work, I write in the metro and in cars, I write when out in clubs, I write at grocery stores and when eating out with friends, I write while walking down the street and shopping for clothes... I write whenever and wherever inspiration strikes me.
If you happen to have an iPhone too, what's your favorite app?