We go over the ways you can purchase all your entertainment over the web

The ”I want it now” syndrome isn’t limited to TV — almost all entertainment media are evolving in the face of rampant consumer impatience. Here’s a quick (and legal) guide to getting your favorite stuff on demand.

MUSIC The simple breakdown: iPod and Apple devotees typically stick with the iTUNES MUSIC STORE, whose elegant design and simple á la carte pricing (99 cents a song) have earned it an estimated 75 percent market share. Trailing behind are RHAPSODY, NAPSTER, and YAHOO! MUSIC (none very iPod friendly), which offer both á la carte tracks and a nifty all-you-can-eat subscription model. eMUSIC.COM is open to all comers, but it carries only independent labels, so the selection is more Bloc Party than Britney Spears.

MOVIES Good news for the sofa-bound: A few online services are now peddling downloadable movies — that is, if you have a broadband Internet connection and a recent version of Windows. (For now, Mac and Linux users should get used to Netflix.) For as little as $1.99 per movie, MOVIELINK.COM and CINEMANOW.COM let users ”rent” selected titles (including Crash and Kicking & Screaming). The flicks are downloaded onto a hard drive; you typically have 30 days to watch it on your computer, or on TV via Windows Media Center.

GAMES If you’re itching for a friendly round of online backgammon, you can’t go wrong with the dozens of games on MSN.COM or YAHOO.COM. (Fun trivia: Women over 40 spend more time playing online games than do men or teenagers.) To relive those countless hours wasted in an arcade, check out GAMETAP.COM, which offers more than 300 classic titles for $14.95 a month.