I have used a USB turntable to rip LP's to mp3 format. I am not an audiophile, and find that the "standard" mp3 format from Amazon MP3 and other sources is quite acceptable when listened to on my iPod or 'puter. Using a USB turntable and associated out-of-the-box software is perfectly adequate for my purposes. There is some hand work involved if you need to record separate tracks, titles, and other tag info, but it's not horrible. I put a link to a review of several options in an earlier link a week or two ago.

If you require high-end audio, this may not be your best bet, but if not, it will get the job done.