Fledgling food-delivery startups using new communications technologies are changing the dining experience for some diners.

Palo Alto, Calif.-based DoorDash, Berkeley, Calif.-based SpoonRocket and Chicago-based GrubHub Seamless each offer a different approach to delivering food fast and at reasonable prices.

“People are just very busy these days, so this is a way for people who don’t have time to go out to dinner, or pick up their meals, to get great meals delivered to them,” said Tony Xu, chief executive officer and co-founder of DoorDash. “For people who don’t want to leave the house for an hour or two, they let us do the work. When people order through us, it’s as if they are at the restaurant already, placing an order.”

A customer using DoorDash goes to its website and picks from a group of restaurants. Then the consumer selects a meal and places the order with DoorDash, which transmits the order to an iPad perched in the restaurant’s kitchen. The restaurant prepares the meal, and a DoorDash delivery person arrives to pick it up. Average time: 44 minutes from order to delivery.

Xu said DoorDash uses algorithms powered by the company’s proprietary software to figure out which driver is best-located to pick up a meal and deliver it.

SpoonRocket provides a much different service. Customers are offered two choices each day, one meat dish and one vegetarian dish.

“We think this is revolutionary,” said Anson Tsui, co-founder and chief happiness officer with SpoonRocket. “Never before have you been able to get a meal consistently delivered within 10 minutes.”

SpoonRocket keeps costs down by limiting the choices to offering only two dishes each day, but the dishes change daily, so customers can sample a variety over weeks or months. The company hired executive chef David Cramer, who led restaurants in Napa and Yountville, Calif.

Both DoorDash and SpoonRocket are challengers in a niche dominated by GrubHub Seamless.

GrubHub’s website offers customers a list of restaurants in their vicinity that offer delivery services. The restaurants pay a 10 percent fee from each order to be listed on the GrubHub website. Restaurants that wish to be listed more prominently pay an additional fee to the online service. The customer pays the restaurant for the food.

“The availability of mobile computing and mobile apps and smartphones are really driving all of this,” said Allie Mack, a spokeswoman for GrubHub. “The new technologies are making these kinds of services really convenient.”

Several restaurants that use the new delivery services touted them as a way to drive more customers to buy their meals. Another appeal for restaurants is that the services free them of the cost of having a delivery driver on staff.

“It would cost us a lot to hire somebody to deliver,” said Mary Minoo Sadri, a co-owner of Vaso Azzurro Ristorante in Mountain View, Calif. “DoorDash leaves ample time for ordering. They always are on time.”

Mistie Cohen, a partner with Oren’s Hummus Shop, a Palo Alto restaurant, said when they began working with DoorDash a few months ago, the delivery service provided the restaurant with about $40 a week in revenue. Soon after, the revenue was up to $500 a week. “The last time I checked, we were getting $2,800 to $3,000 a week from DoorDash,” Cohen said.

DoorDash said it started out in mid-June with about 12 restaurants. Now it’s up to more than 50 restaurants, has made about 3,800 deliveries, and is generating revenue that works out to $1.5 million a year.

Mobile delivery

Tablets, smartphones and mobile computing are making it easier for people to have food delivered to them. Here are three companies with different approaches.

DoorDash

Lets customers order from restaurants, then delivers the meals. Consumers pay a $6 delivery fee and the cost of the food. The service is available in Palo Alto, Calif., and nearby areas.

Website: DoorDash.com

SpoonRocket

Prepares two kinds of meals a day, then delivers the food to customers, who order directly from the company. The charge is $6 per meal, delivery included. The service is available in Berkeley, Calif., and Emeryville, Calif., at present.

Website: SpoonRocket.com

GrubHub Seamless

Delivers meals from participating restaurants, which compensate GrubHub with 10 percent of each sale. Customers pay the restaurant for the food. Chicago-based, has expanded to cities across the country.

Website: GrubHub.com