Hi, I'm hoping to get the name of a movie or any more information at all about it.
Here's what I know;
Comedy, Released between 1997-1999 (around the same time as "Thursday"), Was a trailer on a VHS movie around that time. It had a modern look and feel to it. It was a regular comedy, probably with a light romantic (Guy gets girl in end) theme.

It had a couple of mid-20 guys, crazy about girls. One guy believed that the size of a woman's purse or backpack was an indication of the size of her inner bits and her performance in bed.
Then they show a scene where he's in a clothing shop and they show this hot girl shopping, and she has an absolutely tiny backpack on, the size of a wallet held with small string straps, and it has a leopard skin pattern on it. They cut back to the guy and he's frozen and staring uncontrollable at her, practically drooling.

Any more info would be great.

You're in luck, this movie was shown just this weekend.
The movie you're after is Strange Planet (1999) (http://www.imdb.com/title/tt0209368/)

(Yes I know I answered my own question)

Thanks to all that tried though.
For some ridiculous reason I was thinking of that trailer for years. Finally, no more.

Ha ha ha, so was the film any good then?(did it exceed expectations or had you seen it before)
This back pack business had me laughing! (",)

Nope. It wasn't that good. Haaaa

And it turned out that it was 1 guy had the belief of the backback comparison and it was his mate saw the cheetah backpack. And the reason he freaked out was that he was worried he was turning into the 1st guy. And that was it, joke over. Australian movie and the chick wasn't even hot.

The trailer made it look good. Well done to the trailer people on that one. Unfortunate for me and my 8 year search. It's all over now though, and I'm getting on with my life...

Ha Ha Ha, you are funny. That's almost like the time that I re-visited a film (unlike you) I had watched a few times but over ten years ago... In my mind it was the funniest film I had ever seen and I kept going on and on and on and on about it until one day I found the dvd. My friend (who I had going to on and on about it with) was looking at me as if to say I have issues if I though it was funny.It was called 'the party' and it had peter sellers in it have you seen it?
It really wasn't and I was so disapointed!!
What a let down!