Napster, which on Wednesday was permitted to turn its free music trading service back on, has seen its usage plummet by 65 percent since February, according to a new report. Alternative services, such as Gnutella (LimeWire 1.6b, a Gnutella client, was updated on Saturday) are quickly rising in popularity as a result. Napster will be launching a paid service, with access to some copyrighted materials, later this summer.