In vivo gene silencing in mice

At a meeting this summer, I heard a talk by the company Alnylam about in vivo RNAi in mice using siRNA complexed to liposomal nanoparticles.

I am now starting to see this technique show up in manuscripts. I went to the companies website but couldnt find the particles. Does anyone know where to get these particles? Also what is the efficiency? Are they first pass liver only or do they work throughout the body?

Here is a methods section from a recent PLoS Pathogens Paper using this technique.

In vivo RNAi
C57Bl/6 mice (male, 6–8 weeks) were treated with a single intravenous (i.v.) administration of 5 mg/kg of siRNA formulated in liposomal nanoparticles (Alnylam). Three different modified siRNAs targeting PKC

Alli

Im still struggling with this experiment.  Has anyone out there used RNAi in vivo?  We are considering going with the adenoviral or lenti based systems from Clontech - www.clontech.com/products/detail.asp  just trying to get any help I can at this point?

AG88

we have data showing good knockdown invivo using AAV in mice.