I saw this:

http://www.inmyplaces.com/

you see how the background stays put... what's the code for that?

Put this into the body tag:

bgproperties="fixed"

[View -> Source]

or you may do this in CSS:
body {background-attachment: fixed;}

You can also position the background, have it display only once, have it repeat only across the screen or only down the screen:

(Links and resources on positioning in CSS:
http://www.thenetplace.com/css.php#positioning)

Positioning:
background-position : [top, bottom, centre, left, right];

Repetition:
background-repeat : [repeat-x, repeat-y, no-repeat];


So to position an image in the bottom right corner, not repeating (as is done with the image of the dice on this page: http://www.betsearcher.net/):

background-position : bottom right;
background-repeat : no-repeat;

You can also use percentages and pixels to place the background image:

background-position : 50px 20px;
background-repeat : repeat-y;

The background image would start 50px across and 20px down and repeat down the page only.

Experiment with these selectors until you get a satisfactory effect.