I shopped and learned for 4 years at the avsforum.com. And I shop at Sears, the single best place on the planet Earth for aggressive price matching.
DLP and LCD front projection can not burn in. DLP and LCD rear projection can not burn in. (LCD blue bit-decay is a myth; It does not exist. LCD can develop asomething of a 'ghost' image that resembles burn-in. The ghost can be completely removed by removing power from the set for 15 minutes, thus it's not burn in and not a serious problem. Plasma rot is a myth also.)
Let me ask you something, when your plasma or CRT set burns in ... are these people going to come over and buy you a new set? I think not.
Burn can be minimized by turning your contrast and brightness WAYYYY down. You should also have your set professionally aligned (which you will have to have re-done every 6 months because of drift) and by never leaving a static image on the screen. Static images include menus, Tv station 'bugs' and line tickers, as well as the black or grey side bars on 4:3 and the top and bottom bars on non-16x9 programming.
So, you can crank the contrast/brightness down, always watch a distorted stretch-mode, never leave a static image on the screen, and then suffer when your wife/gf/kids/roommate watches CNN for 8 hours while you are not home.
Or, you can buy and LCD, LCD-RP or DLP-RP and forget about it. My LCD-RP is on for about 20 hours each day, from 6am-2am, most of the time in 4:3 mode or with static images up. It is impossible to use a plasma or CRT in that way without burn in.