We’ve learned exclusively that Chicago-based startup GrubHub, aservice that lets you order food for delivery or take out from local restaurants online or by mobile phone, has raised a whopping $20 million in Series D funding led by DAG Ventures with Benchmark Capital participating in the round. The startup recently raised $11 million in funding in November 2010, and has raised $34 million to date.

GrubHub gives its users access to food delivery service from more than 13,000 restaurants in U.S. cities including: New York, Chicago, San Francisco, Oakland, Boston, Los Angeles, Washington DC, Philadelphia, San Diego, Seattle, Portland, Denver and Boulder. CEO and co-founder Matt Maloney says he expects to list 80,000 restaurants in the next three months and will be in over 26 cities by the end of this year.

GrubHub is free for diners who order and pay for their meals with while restaurants pay
commissions on each order processed. Restaurants that do not currently partner with GrubHub can still list their telephone numbers and menus for free. And of the 13,000 restaurant menus currently available on GrubHub, 5,000 establishments are paying GrubHub to manage and market a white-label online order and food delivery service.

Mobile has also been a part of GrubHub’s expansion strategy, and the startup has launchediPhone and Android apps in the past year that allows users to find the restaurants that deliver near their current location. The apps feature the same functionality as the website, including the ability to view menus, comments, reviews and order, but adds GPS to the mix, making it easy for users to order food from the restaurants near their location.

GrubHub has experienced a 300 percent increase in mobile food orders since last Fall. The company projects mobile orders to make up 20 percent of its total food sales by the end of 2011, which is compared to less than two percent in 2009 (mobile food orders accounted for 10 percent of total food sales in 2010).