I recently received an email from Vihtori who kindly sent in some good tips on useing Realplayer when playing videos.
To fast forward and Rewind in Realplayer, press and hold the joystick UP or DOWN then release when you get to the point you want (just keep an eye in the timer on the right top corner)
To PAUSE and RESUME in Realplayer press the joystick.
To switch between full screen and normal screen in Realplayer use the "2" key on the numeric keypad
If you go to the N91 FAQ in http://www.europe.nokia.com/faqsearch/Search?reg=3&ch=87488&prod=1899&f=1
And search for Video you will get a lot of tips and tricks to encode videos.
You can go up to CIF size (352×288), although this may not improve the quality since the N91 will re-size the video.
Many Thanks Vihtori for your email, im sure the readers will be useing them once they get the phones.