Service uses caching and compression BOSTON — United Online revved up its NetZero Internet access offerings Tuesday, rolling out a high-speed version of its dial-up service, which uses compression and caching technologies to allow for speedier surfing.NetZeroHiSpeed is aimed at dial-up users who want faster access and aren’t prepared to pay for broadband prices or don’t have it available in their areas. The service includes the company’s Platinum Internet service and is priced at $14.95 a month.HiSpeed requires a small software download which the company says can increase Web surfing speed by up to five times the normal dial-up rate by compressing text and graphics on a Web page before it is sent, as well as caching elements of sites that users visit, eliminating the need to re-load data when a user returns to a site. United Online’s new dial-up service comes on the heels of a similar service launched by rival EarthLink last week. EarthLink’s speedy service, dubbed EarthLink Plus, is priced at $28.95 a month and includes priority technical support, eight e-mail inboxes, and 10M bytes of Web space.Both companies gained compression and caching technologies from partners to accelerate their dial-up offerings. NetZero licensed technologies from SlipStream Data, while EarthLink is powering its Plus offering with Propel Software’s Web accelerator.The Internet access providers’ foray into high speed dial-up speaks to the still large majority of Internet users who have not yet adopted broadband service. Technology Industry