Here's another way to invest in the iPad craze, in case you think Apple (Nasdaq: AAPL) itself is getting too expensive: buy memory chips.

I don't mean buying the chips themselves and stashing them in your safe deposit box -- these things tend to get cheaper over time and would make a lousy investment. No, go for the makers of flash memory chips instead. Here's why.

According to a report from IT industry research firm iSuppli, high-speed NAND flash chips for tablet computers will reach sales totaling 1.7 billion gigabytes this year, tripling last year's 428 million gigabyte shipments. And that's just the beginning, as the chips will reach north of 8 billion gigabytes by 2014.

Ten times the memory sales won't translate into ten times the dollar volume, given the pricing trends we already talked about. But this is the flash-chip boost that solid-state drives haven't been able to deliver yet. SSD drives are built around flash chips for many of the same reasons why they're a perfect fit for tablet computers: they run cool, almost always outperform spinning magnetic disk drives, are impervious to bumps and jostles, and take up very little space. Apple got the tablet trend started with the iPad, but others will build on that beginning with Android and Windows products designed to rival the Cupertino gadget.

And they will all need lots of memory chips. That's great news for flash-chip makers Micron Technology (NYSE: MU) and SanDisk (Nasdaq: SNDK), Samsung and Toshiba; the storage systems also need controller chips which brings Silicon Motion Technology (Nasdaq: SIMO), LSI (NYSE: LSI) and Marvell Technology (Nasdaq: MRVL) to the table, licking their chops.

Whether you believe that Apple will eventually win the tablet wars despite being too expensive right now, or that Samsung and others will eat Apple's lunch -- or even that tablets will be great but you don't know who will make 'em all -- flash memory is a safe way to invest in this undeniable trend. In my opinion, Micron is perhaps the tastiest opportunity in the bunch.

Follow Micron, SanDisk, and any other memory players that interest you with our new My Watchlist feature. It's a great way to keep abreast with your favorite stocks with minimal effort.