Amateur Newbie Questions

Question 1)

I studied Electrical Engineering (20 years ago
now...lots of theory and little practice...) I
remember we had access to very expensive RF test gear,
amongst which was a Hewlett-Packard RF Spectrum
Analyzer (US$200,000 (!!!) I seem to remember). A
very, very nice piece of equipment. At that time the
IT revolution/DSP was still very much gathering steam.
Now that PCs with 3.4 GHz processors are available,
plus pretty sophisticated DSP development systems, at
a reasonable cost (several hundreds of dollars), is
there a good homebrew RF spectrum analyzer
available... I've seen plenty of AF spectrum
analyzers available (Spectran etc.) ... What I'm
after is something like:

low cost development board +
high end PC +
GNURadio (or whatever) +
Extensions to GNURadio
--------------------------------
= Pretty (or very) good RF spectrum analyzer

Question 2)

In a similar vein, though of course not as expensive,
Does anyone have circuit diagrams for a homebrewed
function generator, working against an accurate
internal reference, and putting out: pure sinusoids,
square waves, saw tooth functions, white noise ....
etc.

low cost development board (DAC??/Digitally Controlled
Oscillator) + Buffering and Amplification +
PC +
Homebrewed Software
--------------------------------
= Pretty (or very) good software controlled, test lab,
function generator...

Anybody got any ideas...sorry if the answers to these
questions are blindingly obvious!!!

Thanks

Tim