• by Sarah Mahoney  @mahoney_sarah, March 8, 2011

Some 52.4% of Americans plan to celebrate St. Patrick's Day (March 17) -- a big jump from 45.2% last year, and the highest level since the National Retail Federation began tracking the holiday eight years ago.

But most people won't lay out much more green than they did last year, with per-person spending expected to rise less than a buck to $33.97. Total spending is expected to reach $4.14 billion.

The survey, conducted by BIGResearch and based on responses from more than 8,000 adults, found that 102 million people (83.3%) plan to honor the shamrock by wearing something green. And 31.2% say they'll go to a party at a bar or restaurant -- also a record. (The holiday falls on a Thursday this year.)

In addition, 41 million (33.9%) will make a special dinner, 31 million people (25.1%) will decorate their home or office and 23 million (19.1%) will attend a private party, the survey found.

Not surprisingly, younger adults are more likely to fall into the green-beer set, with 33.9% of those in the 18-to-24 age group planning to attend a private party. The survey found regional differences as well. While cities like Boston and New York may think they have a lock on Irish luck, people in the West are most likely to wear green, at 86.4%. And those in the Northeast are least likely to do so, at 78.9%. Men are slightly more likely to get in the spirit of the day -- with 53.9% participating -- than women, with 51%.

Iconosys, which develops mobile applications for smartphones, is hoping to get in on the excitement, offering two free St. Patrick's Day apps. Shamrock Countdown auto-sends a St. Patty's Day morning and afternoon "Luck of the Irish" greeting to friends in your phone's contacts list. And Photo with Lucky lets you take pictures with "Lucky the Leprechaun," then share them via Facebook, Twitter, and email.