Ok I am going to answer clearly to sum things up because both answers to this question are a bit confusing. Technician powers up moves with base power below 60 by 50%.
This boost only occurs once, it does not keep on boosting until the base power is above 60. Example: Scizor with Technician uses Bullet-punch, Bullet-punch has 40 Base power, so this gets multiplied by 1.5, 1.5 x 40 = 60. It does not get boosted by Technician again. Though in this case (I think that this is what Saz meant) Scizor gets STAB from Bullet-punch so it gets boosted by STAB too 90 Base-power, but this is not by Technician.
It is worth noting that moves that hit twice such as Double hit have both of the moves increased by 1.5 not just one, but it is still only one boost per move.
1 Boost per move.