This is pretty cool: http://www.falstad.com/circuit/

While this is not a detailed as something like LTSpice (which is very cool) this is
very useful. While I am not sure if I can get it to simulate HF/VHF frequencies there
a lot things that you can simulate at lower frequencies. You can run this within
your browser if don't want to save it locally.

You can draw out a schematic from scratch or use some of the existing template circuits.

PS... Updated post....

Paul sent me a response this morning to a question about how to scale this into the
HF frequency range.

I am tweaking a simple NPN Common-Emitter follower circuit shown below.

(yes... I know that the picture says 10.1mHz instead of 10.1MHz...
I figured it out after I grabbed the image.)

Go the menu and select options.... other options.

You should see the window below. I changed my "time step size" to 100p. (10p might
give a nicer sine wave depending on what you are looking at.)

Next I edited the value for the signal source. I changed it to: 10.138MHz which will
show up as 10.1MHz

Very cool stuff. I will have to play with the later. It might be an interesting way
to look at Class A vs AB vs B vs C amplifiers in quick fashion. (I don't use LTSpice
enough to quick in setting up simulations especially between AC & DC analysis.)