1 of 13

(The CW)

1.	LAPD's public database omits nearly 40% of this year's crimes
2.	After getting Ron Artest, can they re-sign Lamar Odom?
3.	Iran protests draw thousands but are quickly quelled
4.	Will Ron Artest's act work with Lakers and Kobe Bryant?
5.	The best dunk you'll never see

Singers for hire?

Red Carpet Rewind: Mariah Carey: How to dress like a diva

Hollywood's guide to green-card romances

Mandy Moore rates the top crossover stars

Magazine covers that shook the world

Music stars' standout cameos

After careful consideration, we have divined four main reasons pop stars show up on television shows with such great frequency: 1) It’s a desperate ratings ploy by the network to give advertising execs and marketers something to hype. 2) It’s a desperate ploy by a music label to get a musician some additional exposure. 3) Singers often want to break into the acting biz after making a video or two. 4) The singer loves the show, the show loves the singer -- hey, we should get together and do something sometime!

There is an endless supply of pop stars making television cameos -- No Doubt (pictured) will perform on "Gossip Girl" and The Veronicas will rock the "90210" prom -- but only a few of these have been truly memorable, momentous or successful. Here are a few of the very best.

Compiled by Deborah Netburn, Patrick Day, Todd Martens, Stephanie Lysaght and Kate Stanhope, Los Angeles Times staff writers