I use a GemSound PL-USB ($100 from Guitar Center) with free Audacity software to digitally record LPs. The GemSound has a so-so phono preamp so it can be used alone between your computer and turntable. It also has line inputs so it can be used as XenonMan does with the Behringer. It also has a headphone amp so I can monitor any changes I make with Audacity. Audacity is a pretty complex program and there is a learning curve to consistently convert LPs to digital. I use Audacity to create AIFF files (16/44.1) that are easily managed in iTunes. The process is fairly time consuming but rewarding to have digital versions of music that will probably never be available commercially on CD or via download.

One Audacity tip: Don't add the song's metadata using Audacity. If you do some songs will not play on mobile devices such as iPods and may cause the iPod to lock up. Input the song's metadata after importing them to iTunes to avoid this glitch. As you can guess I learned this the hard way!