I wouldn't do it - You can buy a wet saw for $67 from Harbor Freight. The problem is that inevitably nothing is going to align just right. You'll start laying tile and suddenly realize that what you thought was perfectly square... isn't. So your nice straight cut actually needs to be on a very slight incline. So you measure, you go back to Lowes, you get it cut. You install the tiles. Fuck - forgot to take in to account the spacers, the tile is ruined, and now your mastic is drying. Scrape off the fucking wall, get a new tile/sheet of tiles, go back to Lowes again, cut the damn thing, back home, RE-MASTIC the bastard, place the tile... great - that's one done - how many more trips to Lowes are you going to have to make for this little project??

Or you could spend $67 for a wetsaw. If storage is an issue, sell it on Craigslist for $40 when you're done.