Search Engine Friendly(SEF) URLs

[mySunSite]

Will "SEF" URLS make that big of a difference in my rankings?

For example, will there be a positive improvement if I change from this to this:

www.myfakesite.com/0/22/45/338.php

TO

http://www.myfakesite.com/ponies/hai...sgirlslike.php

Thanks for your opinion!

[OldWelshGuy]

The main benefit of keyword rich domains/url's is that when people copy & paste them as a link, they are keyword rich by default. You just have to weigh up the pro's and con's of that yourself.

[mySunSite]

I'm assuming you're saying yes, that will make a big difference =)

From a technical point of view, do search engines like it? If it was just a straight URL, I see how that would help, but if they put something like "Great something something page here", then would it make a difference to have a keywork rich URL?

Thanks.