I'm wondering if anyone knows of an instant messaging program that will work on a lan. Similar to net send but hopefully a little better interface. Features I'm looking for include:
*Small foot print, hopefully no software to install as far as registry changes. E.g. perhaps could run from a flash drive;
*Possibly simple encryption;
*Easy to use.

Example uses might be:
*Im with buddies in the office at a company where the organization has n o IM program;
*IM with people all staying in same hotel over the hotel LAN;
*Consultants all working in a field office and need to IM without internet access, etc.
Again looking for something like net send but just a little better?