I was rewatching episode 16 and 17, the fight between Renji and Ichigo and I couldn't help but notice how very much like Hollow Ichigo Ichigo was acting during that fight. Most say that the hollow side didn't start appearing until after Urahara help Ichigo regain his powers but could this be the first time it actually appears.
Found this clip of it.
http://www.youtube.com/watch?v=ULL5L...rom=PL&index=4
Look at how he moves and his facial expressions (smiles, eyes, etc). Very Hollow Ichigo. I keep thinking (and this could be because I haven't seen the episodes where Ichigo regains his powers in a long time) that what Urahara does to Ichigo to help him regain his powers doesn't create the Hollow side of him but actually simply unleashes it as it has always been there. The first time being the fight with Renji in the world of the living.