I posted about it in the "NL Q&A" topic a while ago, and is one of the thing that I use to effectively remove roughness that is due to node handle lengths...
Just select one segment at a time and press 'I', repeat so you have done it to all the segments you want to smooth, then select all of them ant "Ctrl + G". It will need to have a good amount of nodes for this to work perfectly, but it can really make a difference pretty quickly...