Using Photoshop to creat Bokah effects

[Belano]

Any CSers care to teach me how to creat bokah effects using photoshop? I try using gaussian blur and layer mask but the effects are not that great. Seem as if the clear image object as been cut and paste on a blur background. Any advice?
Is there any tools around can creat such effects too?

 

[roygoh]

http://roygoh.clubsnap.org/gallery/album40

 

[espn]

http://megaweb.clubsnap.org/articles/pstips/ps6_bg_blur.html