Blown Head Gasket, or something else?

[RobbieKnobbie]

I had my 2006 Boxster S out for a leisurely drive last night and noticed at a stop along the way that there was a slight sweet, coolant, smell to the exhaust. I'd always seen a little white puff on start up, but I'd never noticed the smell before.

Supporting evidence...
06 Box S
57k miles
I've never seen the temp gauge go above 175 since I've owned it (2k miles)
I had the emissions tested some two months ago and it passed without issue. (would a state emissions test pick up coolant?)
The coolant level looks a little low, but the idiot light hasn't come on
No dipstick, so I can't see if there's discoloration to the oil
motor is completely stock
oil was changed 3 weeks ago, no water was noticed (but the engine was hot so it would have boiled off anyway)
The oil level since has been high

So I guess my questions are...

1. is there anything *other* than a blown head gasket/ cracked head that this could be?

2. would a blown gasket throw a code? I connected a friends generic OBD reader and it didn't find any stored codes.

Thanks guys!