Does the Americans with Disabilities Act apply in cyberspace? Without clear guidance from the courts, companies are deciding for themselves. Pressured by advocacy groups, some businesses have already taken steps to make their Web sites more accessible to the disabled. But other companies have said that while they’ll voluntarily alter their sites, they aren’t required to do so by the ADA.

RadioShack Corp. is the latest company to reach an agreement with advocates for the disabled. On June 13, the Fort Worth, Texas-based electronics retailer announced that it would make several improvements to its Web site for users who are visually impaired. The agreement grew out of negotiations between RadioShack and the American Council of the Blind and the American Foundation for the Blind.