Hidden Weapons optimization might be another natural choice for factotums. If I remember correctly, some of the tricks made drawing a hidden weapon a standard action, so more standard actions are always a good thing, especially combined with iajutsu focus when drawing.
I'm using some hidden weapons tricks for my latest character in Iron Kingdoms. IK lets you throw 2 throwing knives with each attack, and has a ton of hidden weapon equipment. There is a hidden holster for knives that lets you draw them as a free action, or you can combine a melee weapon with a gun: on a successful melee attack, you then can shoot the gun at +2 as a free action, and your opponent is flat-footed against the attack.
There are also gun holsters for the sleeves, collapsible batons and staves, staff-spears, collapsible bows, spring-loaded blades, etc. All stuff that is elsewhere in D&D as well, but nice for a stealthy character anyhow.