What type of vids? .mpg, .wmv, .flv, mp4, divx?
You need a player that will play the type of videos you have.
Do a google search for the players you want.
Most of my videos are divx so I have installed the mobile divx player on my N73. It is very good, but to save space before I download movies to my N73, I use the divx converter to convert my hi def divx files to the qmobile format - it brings full movies down to around 200KB. The basic mobile format gives slightly better definition but has larger file sizes - so I use it for music videos.
The native player provided with the N73 will play mp4, and that's about it.