For recordings demo's and sketches on my laptop while on the road I am looking for a USB mic. I found the Behringen C-1U:

http://www.behringer.com/EN/Products/C-1U.aspx

Is that one a bit okay or are there any (really) better ones (in the same price range!)?

I understand you are wanting something portable for the road, but I would not recommend a USB mic unless it has output on it as well like the samson G-Track.  http://www.sweetwater.com/store/detail/GTrackUSB/

the G-track is not just a mic, but has output available also.  IMO that's the most important thing if you feel you need a USB mic.  USB mics without output are terrible for recording because you'll be trying to use two different clocks - one for the mic and one for the onboard soundcard for output.  sync problems are inevitable with 2 different clocks.  and that's only if you can get the hardware to play nice with each other.  you will likely have to use MME driver mode to get both the USB mic and the onboard soundcard to work together.  MME is the highest latency protocol and will cause you problems if you need to monitor what you're mic'ing while you're recording.

the G-Track is a full soundcard and can be set up for input and output.  you can connect headphones for output and monitor directly from the mic while recording, and you can also use it for playback just like a typical USB soundcard.

it also even has a line level input if you need to connect a keyboard or mic pre up to it from another source.

that's my recommendation.

For what you stated..... simply sketching out ideas.... I guess a USB mic might be OK. 

If you don't already know it, a USB mic is really not good for much of anything when it comes to doing multitrack recording. Some people can get them to work properly and sufficiently for recording but the majority of people who buy them to use experience major issues when trying to get them to record properly in Sonar products. The tracks tend to be out of sync and latency issues abound. 

However, for capturing that single audio track in a songwriting session....it probably will be OK. They tend to work fine as long as you don't try to sync tracks up in a project. 

For what you would pay for a mostly useless USB Mike you would be better off buying a mini recorder, like a Tascam or Zoom. Or even just use the built in mikes on the laptop. USB mikes HATE Sonar.

For what you would pay for a mostly useless USB Mike you would be better off buying a mini recorder, like a Tascam or Zoom.

+1! Plus they're small enough you can always have one with you should some interesting sound present itself during your travels. Some of them have multi-track capability, most use standard memory modules, most can record directly to MP3 for maximum storage capacity, and all are capable of high-quality wave files that you can transfer into your laptop later. I've even heard of people using them as USB microphones.