There is also the Instruction skill from Mercenary.
Yes, but that has it's own problems;
1) it doesn't save you that long - 1-6 days sounds good but not when training requires a month or two.
2) It requires two checks, one for the instructor and one for the instructee
3) The number of people you can instruct is dependent on the effect of the check, making it unpredictable and quite low unless you have a very high Instruction skill
4) You can only pass on a skill you already have up to a level below your own skill, so it doesn't help the party get new skills, just spread them around
5) Beacuse of the aforementioned way learning new skills works, the need to have a high Instruction skill means that the instructor take much longer to increase his other skills than he otherwise would.
There is often criticism of people who say they want a faster/better/different mechanism for improving their character. Perhaps they just enjoy role playing their characters efforts to improve more than their financial bottom line or equipment; I believe the more typical Traveller 'rewards'?
That's the way we tend to play it. We usually find adding contacts and allies is a more interesting way of progressing a character, and it allows you to throw in additional skills at the party's disposal without them needing to go off to university for a year and a half.
For example, when my lot needed to know something about pre-imperial history in the region, rather than spending four or five months trying to develop Social Sciences (History)/1, you go and talk to Professor Beale, who is well disposed(ish) to most of the group after some work they did for him.