I just returned from Los Angeles where every coffee shop is full of earnest people working on their laptops, writing the next Great American Screenplay (many pages of superheroes, explosions, drones, etc.).
Starbucks and some others provide abundant power points so battery power becomes irrelevant and now the fact that some writers stay for hours after buying one cup of coffee is becoming an issue. Some coffee shops have removed the power points, others have put up signs suggesting that an hour or so is a reasonable time to linger over one cup.
If you like writing with the sound of a coffee shop but don't have one handy (or they throw you out after an hour...) there are several sites that allow you to listen to coffee shop background noise.
One is coffitivity.com (corrected link). It's also available as an app for Mac desktop, iPad & iPhone and Android).
Another is soundrown.com--there you have the choice of coffee shop (a bit noiser than the one at Coffeeitivity), waves, birds, and fire (as in fireplace ).
If where you normally write is too quet, or the wrong kind of noisy, using headphones with one of these can help (especially noise-cancelling headphones). You may get the same benefits as working in a coffee shop--but with cheaper coffee and no chance you'll be evicted after an hour.