Use of IM for Corporate Communication

Our company is interested in using IM in our customer call center. We have been reviewing the technical specifications for two products – ICQ and Yahoo IM. We have already eliminated the Yahoo product, as we are interested in limiting the use to ourcorporate LAN only. I am curious to find out what other companies are doing for IM in their call centers. I have seen headlines in the trades, but not had much luck finding well constructed IM software – and I’m not impressed with ICQ. Any input from the Republic members wouuld be greatly appreciated.