Might I suggest the: iMic from the company: Griffin Technology
Here's the trumpet blowing stuff:
The Griffin Technology 9066-IMIC2 iMic/USB Audio Interface, the original USB audio adapter, lets you connect virtually any microphone or sound input device to any Mac or PC system with a USB port. iMic supports both mic and line level inputs via a selectable switch, and has a variable level output for connecting speakers or headphones. The iMic really shines as the essential tool for converting your old LPs and tapes into MP3s and CDs. Griffin's audio recording software, Final Vinyl for Mac OS X (provided for free exclusively to iMic owners), makes recording old records and tapes very easy with its advanced features, including waveform-based cue editing and built-in 10-band EQ. You can use Final Vinyl to equalize LPs without having to connect a turntable to a pre-amp. iMic is also an ideal solution for your podcasting needs and for use with GarageBand, iMovie, and Final Cut Pro.
Translation: If you have a device with phone cables, you can record from it to your computer.
There's a bit of a learning curve to it mostly, not letting the input levels get too high, this causes very unpleasant results. The software will display a visual image of both stereo channels, just don't let the levels go above the top of each display. The other slightly tricky bit is the recording time setting, I'm not sure what the default is at the moment but it is immensely annoying when recording stops because you didn't know about the default time.
Using the iMic is much cheaper than buying a usb turntable and you don't have to get rid of the turntable when you have finished with it.
Hope this helps.
I should have added: It is always advisable when recording audio/visual, to ensure that you have as much contiguous free disc space as possible.