Hello, guys,
I'm looking for a small, portable and affordable ($100-$150) USB interface to throw in my laptop bag, for songwriting purposes when on the road.
I'll be using it mainly to write and record ideas in Sonar with TH3, no more than 3-4 tracks per project.  
One input ok, but something with good drivers as low latency is a must.  
 
So many cheap devices available out there, just want to make sure I get something half decent...so I would like some feedback from current users.
 
Any recommendations?
 
Thanks!

I have a Focusrite Scarlett (2nd gen) and I'm happy with it. I've also heard good things about the Tascam US-2x2.
 
Here' a list that might help you narrow down the choices:
http://www.musicradar.com/news/tech/the-best-budget-usb-audio-interfaces-in-the-world-today-570850

telecharge
I have a Focusrite Scarlett (2nd gen) and I'm happy with it.

Thanks for your suggestions.
Which Scarlett model do you have? I used to own a 2i4 but looking for a smaller device. The Solo would be the one Focusrite unit I would consider.
 

I have the Solo, but I have heard the 2i2 is better. This is second-hand information, but might be worth looking in to.

A friend and I use a Scarlett 2i2. 2nd gen. USB 2.0
Two neutriks, a headphone out, and l r mains out. Only USB bus powered.
Easy install and works well. Simple.

edit 
Was recommended by about 4 people on one of the Facebook forums when I was looking for a portable.
 

I use a Focusrite Scarlett as well (mines a little bigger than a solo) but here's another nod for the Scarlett's.
Mic Pres are really good for cheap money.

The Solo would be your best bet, My son in Law just bought one and it's perfect for one person and laptop use for playback. Just don't plan on using a fancy Condensor mike as there's not enough Phantom power for some mikes,,
 
 
 
That is the down side of Buss power only. It's nice when they give you both options like the Tascam 2x2. 
The Tascams are bigger than the Scarletts. I like my 6i6 for travel it pretty small and covers a lot of ground as far as features. The 2i2 and 2i4 are the same box.  
 
But be warned, you are not going to get true low latency performance from any interface under $500. You'll be in the "hidden buffer" zone with those. Best is going to be around 5-8ms RTL. Which might be fine for you. Below those RTL specs your looking at Motu, RME etc. 

The RCA outs are another thing to consider with the solo (whether they are acceptable or not for your needs).

The steinberg UR 22 is a good choice.
The in - out  latency is lower as of the focusrite scarlett series -
but  the preamp of the scarletts is imo minimal better and the headphone-amp 
a little louder .
I made some (mobile)voc recordings with the UR22 thought as a demo last week.
To my surprise the tracks sound good , so that I don´t have to record that again.