MINNEAPOLIS (WCCO) — This is a big day for anybody who owns a cell phone, not just the folks who have iPhones.  True, the big news is that the iPhone 4 became available at Verizon, after years of exclusivity at AT&T.  But the chain reaction could save us all a lot of money.

With plenty of fanfare, and a rush of customers at its Roseville store, Verizon started selling the iPhone early Thursday morning.

“My wife and I have been waiting for Verizon to get the iPhone forever,” said Jason Isaacson of Shoreview, who got to the store more than an hour before it opened.

Still, other carriers are not sitting on the sidelines. AT&T, Sprint and T-Mobile are all offering deals this week, targeting folks who may be near the end of their two-year contracts.

“Just like in the movie ‘The Seven Year Itch,’ often consumers right about month-18 will start to get a little Two-Year Itch, and start wondering what else might be on the market for them,” said mobile marketer Lisa Foote of MixMobi, who is actually in that position herself.

And with so many discounts to choose from, she said the timing is right.

“I think this is a great day,” she said, “a great week, especially if you are either out of contract, or about to become out of contract.”

So, what about the rest of us?  It doesn’t hurt to call your carrier, which is what some of our co-workers did.

Paula got a new phone from T-Mobile, and saved $7 a month.

Sonya upgraded her Sprint phone, and saved $30 a month.

And Cassie got AT&T to knock $35 apiece off the iPhone bills for her husband and herself.

Everybody’s situation is different, depending on how close they are to the end of their contracts, but the carriers all want to keep your business, so the experts tell us it’s always worth a call.