Cisco Systems Inc said on Friday it plans to buy privately held Jabber Inc, which specializes in instant messaging software, to bolster its own line of Internet-based communications products.

The two companies did not disclose financial terms.

Denver-based Jabber provides open instant messaging technology that supports different devices and applications, and allows users on separate networks, such as Google Talk or Yahoo Messenger, to connect with each other.

Apple Inc. on Friday advised iPhone 3G users in many countries to replace the device’s power adapter following reports that metal prongs broke off and stuck in power outlets, creating a risk of electric shock.

Apple said it will exchange the ultra-compact USB adapters for a redesigned model, without charge, in retail stores and online starting Oct. 10.

In the meantime, iPhone 3G users who received the tiny USB adapter with their phone or who bought it separately should immediately stop using it. Apple said iPhone 3G owners should use its standard USB power adapter, which has fold-up prongs, or charge the device by plugging it into a computer.