Think twice before you copy someone on an e-mail or hit “reply all.” Such practices have made today’s workers less productive, a research firm concludes.

After years of naming a product or person of the year, Basex Inc. decided to forecast “information overload” as problem of the year for 2008.

Workers get disoriented every time they stop what they are doing to reply to an e-mail or answer a follow-up phone call because they didn’t reply within minutes. Basex chief analyst Jonathan Spira said workers can spend 10 to 20 times the length of the original interruption trying to get back on track.

He estimates that such disruptions cost the U.S. economy $650 billion in 2006.

Spira has a number of recommendations: Resist the urge to immediately follow up an e-mail with an instant message or phone call. Make sure the subject line clearly reflects the topic and urgency of an e-mail. And use “reply all” sparingly.