SE reputation and privileges system is well balanced: we do not trust new users we know nothing about until they earn the community trust by participating in SE activities.
However, sometimes for new users it is very difficult to get started as the basic privileges are very restrictive. For example, a colleague of mine, a brilliant programmer, hesitated when I encouraged him to use SO because of this barrier placed to guard SE from unknown users.
I propose a new feature: "an invitation to SE", a trusted user (X reps and up) will get a bank of invitations he/she can use to invite people they know and trust. A new user that was invited will start with enough reputations (I believe 15) so that he has no "new user restrictions", (instead of 1) reflecting the fact that by invitation he is not a stranger to the community and deserve to be trusted with some privileges.
I believe a somewhat similar "invitations" mechanism was installed recently in SE careers website.
UPDATE: (Aug 6th,2015)
Regarding concerns raised by Catija:
- a "walk-in" user cannot be trusted at first because we don't know him, in contrast we (or at least someone) knows the "invited" user and believe he/she can be trusted to a certain extent. Maybe trusted just enough to remove the "new user" restrictions.
- I don't think invited users deserve the rep-boost, but it's the easiest way I could think of to remove the "new user restrictions" -- if you have another way of achieving this goal it should be just as good for this feature.
- The most significant barrier is the restriction on leaving comments: during the time I am active is SO, this restriction was the most "painful" for new users.
- How to prevent "abusing" of this mechanism? well, first, I think "invitation" privileges should be given only to "trusted users" (I believe 20K reps and up). These users care about SE, knows how it works and we trust their judgement when they invite users that can contribute to the community. Second, there will be given only a restricted amounts of invitations per trusted user to "hand out", he/she should only get more if the users that he/she invited are indeed "good" users (i.e., gained extra X reputation over T days). Thus we can control the amount of invitations that can be handed out. If this features works well more invitations can be given to trusted users.
Status: (Aug 13th, 2015)
Judging by the answers/comments/downvotes I guess that's a "no" for this feature request. Well, was worth trying pushing this idea. I appreciate the feedback. Thanks.