Thought I'd add to the various techniques for collecting yeast based on my setup. I have a 14 gallon conical. I typically will pitch up a yeast starter for my first batch. After fermentation is done, I cold crash my beer, still in my ferementor, to 32F. I let the beer sit at this temp for a few days and then transfer the beer to carboy thru the racking tube in the conical.

I then boil a 1/2 cup stainless steel measuring cup and a 1000 ml Nalgene bottle. After boiling for 15-20 minutes, I pop the top off the conical, carefully reach in and scoop up 2 or 3 measuring cups of yeast and put it into my bottle. I add a bit of sterilized water to the bottle, put it in the fridge and am ready to just pitch the contents in my next batch. Works great. Be mindful of being clean in all the xfers and you should never have a problem.

This works for me.

Chris, if you have a conical, why don't you get your yeast from a bottom port?