Verizon is offering its HP Mini 110 netbook for $29 while supplies last. It’s no MacBook Air, but it’s an easy-to-carry downsized Windows laptop. The promotional price is available throughout the United States, a Verizon spokesperson told me.

It’s a classic give-away-the-razor-to-sell-the-blades tactic. What Verizon is really doing is signing up $59 monthly 3G wireless plans for its netbooks. The $29 price for the hardware is only the entry point. You’ll need to pay $177.49 up front for a Mini plus taxes in California. Verizon will send you a $100 prepaid credit card as a rebate if you mail in the barcodes from the side of the netbook’s cardboard box.

A 5GB per month Verizon 3G service plan is $59 per month plus taxes and fees, billed at the end of your first month. I bought one. Verizon estimates my first bill will be around $180. After that it will drop to under $100 per month.

The Mini 110, as CNet reviewers wrote, isn’t the world’s greatest netbook. I bought one and spent an hour working on it at the Marriott hotel’s 39th-floor view lounge last night. Verizon’s connection dropped off once, but was usually 5 bars strong with 500 kbps download speed. Much better than my AT&T iPhone.

Biggest gripe about the Mini 110: Its 10.1-inch display only has 576 rows of pixels, which means you have to scroll your browser window up and down a lot. And it takes more than a minute to reconnect to Verizon after waking the thing from standby mode.

But still, twenty-nine bucks. Verizon offered this price on Gateway notebooks last year on Black Friday. This time, it’s a clearance sale rather than a loss leader. That suggests that super-low netbook prices may become commonplace. If AT&T can subsidize $350 of the price of an iPhone, there’s no reason wireless carriers can’t subsidize the entire price of a netbook. Verizon has proven that they will.