There was one more symbol in some un-obvious place, and I just can't think of it.

Or maybe i'm thinking of a ambiguous smudge from fingerprints on my TV. ;p

There should be more symbols in next week episode's too. Can't wait.

A frequently appearing symbol linked to the new heroes strongly resembles a stylized RNA molecule. This symbol has appeared numerous times so far, frequently in some way related to a 'special' person:

* On the front cover of Activating Evolution by Chandra Suresh.
* In the swimming pool at a double homicide that Matt Parkman was investigating.
* As a recurring shape shown in a genetic profiling program created by Chandra Suresh.
* On a drawing done by Peter Petrelli.
* Frequently painted by Isaac Mendez.
* On the cover of 9th Wonders comic book #14.
* Written on a textbook owned by Claire Bennet.
* On the necklace of the unidentified man working with Mister Bennet.
* Written on pictures in Sylar's apartment.
* As a tattoo on Niki Sanders's alter ego's shoulder.
* As a symbol on Hiro's katana.
* On a post-it note on Chandra Suresh's map.
* Revealed in an underlayer on a painting of Niki Sanders in the same spot as her alter ego's tattoo.