It turns out that the unlimited talk plans the major operators announced last month were just the beginning of their experimentation with new service plans. In the last two days, Verizon Wireless and AT&T have introduced new service pricing for data and business services targeted a specific use cases for their evolving customer bases.

Verizon made the biggest leap offering for the first time a data plan not tied to a laptop card that requires no voice service. Akin to the naked DSL offering its wireline counterpart has explored, the data-only plans charge from $35 to $55 a month, depending on the device and the use-case, but most significantly they include no compulsory voice plan. Customers can make and receive calls at per-minute rate ranging from 25 cents to 40 cents, but otherwise have no voice contract or minute bundle. The cheaper plans are for standard feature phones and include unlimited browsing, SMS, MMS and data usage, while the next two pricing tiers are geared at BlackBerrys and smartphones, tacking on additional charges for e-mail. Verizon also created an option for smartphone users who still talk every once in a while, charging $30 a month for the unlimited data with a standard voice plan attached.

VZW said the new plans are in direct response to customer feedback and are targeted at customers—particularly the deaf and hear-impaired--who primarily use their phones as data and messaging devices. But Verizon seems to be tapping into a larger trend of mobile data, exemplified by the recent revelation that iPhone users spend more time looking at their phones than talking into them. These data only plans could be precursors to the wholesale and partner plans that Verizon offers to third party handset makers and service providers under its new open development initiative. Presumably some of the new devices that come out of VZW’s developer program will be data-only or data-centric devices tapping into the 3G EV-DO network, but not necessarily the 1X voice network.

AT&T target wasn’t hard-core users, rather small businesses. It took what is essentially a family plan and converted it into a business plan. The family members, in this case, are employees all of whom share a pool of minutes. Starting at $60 for up to five users and a pool of 700 minutes, the service scales up to 40 users and pools as large as 20,000 minutes a month (no word on whether there is rollover with that). AT&T said that there are 10 million U.S. businesses that have less than 100 employees, so its potential customer base certainly isn’t small.

Neither operator, however, has yet to match Sprint’s Simply Everything initiative, which bundles unlimited messaging, data and voice into a single $100 a month plan. The other operators are willing to put unlimited voice on the table for $100 a month, and Verizon’s announcement this week shows they are willing to reconsider how it sells data, but they aren’t likely to stick everything under a single flat-rate umbrella just yet.

In other services news, Verizon said it is now offering a hosted e-mail service targeted at small businesses without access to pricey push e-mail servers. Offered as both a basic and a premium service ($8 and $15 a month for 25 MB and 100 MB of storage respectively), the Oz Communications-powered platform synchronizes POP3 and IMAP e-mail with a data-enabled phone.

T-Mobile also signed up Juice Wireless as a social-networking provider for its network. Among the dozens of new-breed mobile-only social networks that have sprung up in wireless, JuiceCaster has been a stand-out, landing on the decks of Alltel, Leap Wireless’s Cricket Communications and U.S. Cellular. T-Mobile is by far it’s biggest U.S. deal and it’s first Tier I operator customer.