With the Intense Training perk, you can put a single point into any of your S.P.E.C.I.A.L. attributes.”— Fallout: New Vegas
With the Intense Training perk, a single point can be put into any S.P.E.C.I.A.L. attribute. Each point will be fundamentally identical to a point that had been allotted during character creation, and so will allow the player character to gain more implants (Fallout: New Vegas) or perks.
In Fallout 3, taking this perk at level 2 to increase Intelligence by 1 gives the player 18 more skill points by max level (28 with Broken Steel installed), which is considerably more useful than any of the skill-raising perks available at that level.