You've done your Internet search. Tantalizing links clamor for your attention. But it's hard to know which might contain spyware or throw you into the clutches of a spammer (see "Malware Menace").

A Boston-based startup, SiteAdvisor, is beta-testing a tool to sort the good from the bad. With SiteAdvisor's software, one of three icons will appear next to many links -- a red X signifying "stay away," a yellow exclamation point suggesting reason to worry, or a green check mark for the all-clear. If you visit a site, warning balloons may pop up saying things like "After entering our e-mail address on this site, we received 197 e-mails per week. They were very spammy."