If you're on a tight budget then you won't find a passable 2 channel USB audio interface for less than the price of the Lexicon Alpha.
Back when this was first released in 2006 Lexicon promoted it as a professional device which produced studio quality results, but let's be honest - times have changed and this is no longer studio quality. It's not that there is anything terribly bad about it, it's just that maximum sampling rate of 48kHz is only half what you need to earn the label "professional" these days.
There are two purposes I would use this for:
1. Live performance
The quality is certainly good enough to use at gigs. For example you might want to use it to plug your guitar into your laptop so you can use amp modeling and guitar effects software.
2. Personal use or Recording Demos
If you are only recording music for personal use you don't need to spend a lot of money to do that - it usually sells for around $60. I would not use this to record music intended for commercial release.
With those caveats aside, it will get the job done and it's really hard to beat the low price.
On the brighter side, it comes bundled with Cubase LE5 which although it has long since been superseded by Cubase Elements (the current entry level version of Cubase), it's still quite a usable DAW and you can start recording music right out of the box.
One highlight is that it also comes with a free copy of Lexicon's Pantheon VST reverb plug-in.
- It's dirt cheap and you can usually get it for about $60.
- The bundled software is worth the price alone.
- A power adapter isn't required - it draws it's power from the USB connection.
- It only has one XLR microphone input.
- The sample rate is too low for professional recording purposes.
- It can't be used with condenser microphones unless they are self-powered or you have a separate mic pre-amp with phantom power.