There always seems to be restaurant news on the menu. As we do every week, let's review some of this week's more appetizing stories.

1. 10 friends for a Whopper
Burger King (NYSE:BKC) is at it again. The fast-food giant's cutting-edge marketing campaign has taken another daring promotional turn. Burger King launched a Facebook app that will reward users with a free Whopper if they delete 10 of their friends.

Unlike the quiet "defriending" process on the popular social-networking site, the 10 deletions will be listed in the public-activity feed as being "sacrificed" for a Whopper. This may sound like a clever idea, but you know it's going to ruffle a few feathers in the Facebook community. The site also is unlikely to appreciate seeing its viral networks shrink in the pursuit of a burger.   

2. Goodbye, Ruby Tuesday
A disappointing quarter out of the casual-dining niche shouldn't surprise anybody. However, even with lukewarm expectations, Ruby Tuesday (NYSE:RT) delivered a stinker on Wednesday. The company posted a steep fiscal second-quarter loss, weighed down by $56.2 million in pre-tax charges for the restructuring of its portfolio and for writing down its goodwill. Revenue also fell, bogged down by a whopping 10.8% slide in comps at company-owned eateries.

"Fiscal 2009 is the most difficult year since our founding nearly 37 years ago," its CEO notes. The company expects comps for all of fiscal '09 to fall by 9% to 10%.

3. Sonic unleashed
Drive-in chain Sonic (NASDAQ:SONC) posted a fiscal first-quarter profit of $0.12 a share this week. Earnings came in well below the $0.22 it rang up a year earlier. Comps fell by 3.6% during the period, a grim contrast to the larger fast-food chains that have no problem luring penny-pinching patrons. CKE's (NYSE:CKR) Carl's Jr. did post a small dip in comps for December, but that drop was more than offset by healthy gains at its Hardee's chain. 

So what's eating Sonic? Is it the whole "eat in the car" thing and the fear of consuming too much fuel in a soft economy? One would think that folks consume more gas in a busy BK drive-through lane than they do by parking in front of a Sonic.

Either way, Sonic isn't taking any chances. It's following the fast-food herd by offering up a value menu as a way to attract deal-seeking customers.

4. Crossing the border
Chipotle Mexican Grill (NYSE:CMG) (NYSE:CMG-B) is expanding overseas. The popular burrito-rolling chain announced that it will open its first location in London by the end of the year.

Chipotle is also spicing up its executive ranks. CEO Steve Ells will now be sharing the helm, as president and COO Marty Moran is being promoted to co-CEO. Moran has been with Chipotle for four years. The quick-service chain is also hiring its first chief marketing officer, a good move given decelerating comps in recent quarters.

5. Rocky Mountain lows
We're even cutting back on chocolate these days. Rocky Mountain Chocolate Factory (NASDAQ:RMCF) delivered weak third-quarter results. Revenue fell by 15%, with comps at franchised units slipping by 8.1%.

The more problematic part of the report is that the pounds of product purchased fell by a whopping 24% on a same-store basis. If orders are falling substantially more quickly than sales, franchisees must be fearing the worst in this economic slump as they scale back on their inventory levels.

Rocky Mountain is still profitable, though. The end result for the quarter is net income of $0.14 a share, less than the $0.19 a share it earned a year earlier but still firmly in the black. 

Check out this week's dessert specials:

Chipotle Mexican Grill is a Motley Fool Hidden Gems selection and a Motley Fool Rule Breakers pick, and the Fool owns shares of it. Try any of our Foolish newsletter services free for 30 days.

Longtime Fool contributor Rick Munarriz is the rare foodie who embraces restaurant chains. He owns no shares in any of the companies in this story. He is part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.