Several people have asked about when we will offer solid state—or flash-based—hard drives. User reg submitted it on IdeaStorm, and there are several related ideas about these drives as well. Today, we're selling them on our ultra-mobile notebook the Latitude D420 and the D620 ATG semi-rugged notebooks. We will also offer these drives across our entire next-generation notebook line.
I found the drive available separately as an offering for your D420 here:
32 GB Solid State Parallel ATA Hard Drive for Dell Latitude D420 Notebook - Customer Install
Its only 32GB right now. I wish their were some benchmarks we could get on these.
You can buy the disk direct here
(Hmm... even though it has the buy direct link, I can't seem to find it in the store!).