There are a bunch of complaints about the number of tech trades between the AI's. Here is
an algorithm that might 1) be easy to implement, and 2) address the problem.

Suggestion:

Put in a slider with which the player can specify what percentage of total research points may
be acquired by trade. For example, assume that the total research points of all the techs an
AI has is 10,000 points. If the player selected 50%, then at most 5000 of those points could
have been acquired by trade. The other 5000 would have to have been researched by the
AI. The same restriction applies to the player, of course. In this example, for every 1000 research
points worth of techs a cilivization acquired on its own, it could go out and trade for another
1000 research points worth of tech.

Further, AI's will not trade a tech if it is uniquely owned by that civilization. Hence, if a race has the
most advanced beam weapon in the galaxy - it will hold on to it. It represents a major advantage
to that civilzation.

This will give the player an easy way to control how much tech trading there is in any game he
plays. He can set the slider to "100% of tech must be researched" to play a game in which no
tech trading is allowed, or to anything in between.

This should promote the races (and player) specializing in only a few areas, and trading (or buying)
for lower level techs in the other areas.

Another idea is that the % of tech points that must be researched v.s. can be traded for could be
(slightly) modified by a races basic (pre-tech advances) diplomacy level. A highly diplomatic
race could acquire more tech via trade then a race with a lower diplomacy level.