There's no widespread standard like AGP for laptops yet, but ATI and Nvidia are trying to push their technology.
It's possible Dell might offer a proprietary upgrade, but you'd have to call them for that. You're chances aren't good though, but good luck to you.
<b>Radeon <font color=red>9700 PRO</b></font color=red> <i>(o/c 332/345)</i>
<b>AthlonXP <font color=red>3200+</b></font color=red> <i>(Barton 2500+ o/c 400 FSB)</i>
<b>3dMark03: <font color=red>5,354</b>