Including Walmart, which sells cellular phones, offers cellular service, and is regulated by various government agencies. Like the Maine Bureau of Taxation, Workers Compensation, IRS, Social Security, and so on. I was also told by Code Enforcement that Sprint PCS is a public utility because they provide similar services. Similar in that it is phone service, and Bell Atlantic provides phone service. Northern Utilities is a public utility that sells gas.
Gas stations sell gas, which constitutes a similar service.
Clearly this tower represents a commercial structure being built to rent space to private commercial businesses. By calling it a public utility facility, and by calling Sprint PCS a public utility, this commercial structure will be built in the middle of a Residential District A Zone. Where it otherwise could not be located. The Telecommunications Act of 1996 is lovingly referred to as the National Lawyers Relief Act based on all the litigation it has spurred across the country. This piece of legislation was bought and paid for through the lobbying efforts in Washington.