So I read a lot of good things about Asterisk. I am not however looking to run a call center or small business setup. I am still interested what potential uses it has for me as a "power user" and what features I could harness for my communication needs.
Of course, if you want to enjoy the highest quality audio then use FreeSWITCH because it supports audio codecs at multiple sampling rates and bit rates. It also has a Skype module (recently renamed "Skypopen" from "Skypiax") that will piggy-back off of the Skype client and handle the high def audio from Skype's SILK codec.
Other things you can do with Asterisk (or FreeSWITCH) would be things like answering incoming calls and handling them differently based upon the caller ID presented. Known telemarketers could be sent to so-called "torture" scripts that play fun little pranks on those calling. You could also route certain callers to a follow-me setup where, so if your kids are calling you could have it ring to your cell phone after ringing the home phone for 12 seconds, but if your boss is calling you could route it to a message saying, "Your call is very important to me, please leave a message and I will return your call at my earliest convenience..."
The are many things you can do with OSS telephony. I'm a HUGE fan of FreeSWITCH but that doesn't that I think you shouldn't look at Asterisk, YATE, OpenSIPS, etc. if you are curious about telephony.
I vaguely remember someone suggesting that with your own asterisk server, you could add a gateway to your network which would route skype call to your standard SIP IP phone.
The thought of being able to answer skype calls using your normal voip phone is quite appealing, but I haven't had the time to look into it any further. Plus, if you have both a SIP IP Phone and a Skype phone on your desk at the moment, it should allow you to get rid of the latter and give you a single device to answer POTS (analogue), standard VOIP (SIP) or proprietary VOIP (Skype) calls.
One of the niftier home uses I've seen for Asterisk is that you can set up a Linux box as a home theatre server, and run Boxee or some such software. That same server can also run Asterisk and display the caller ID of the person calling on your TV, and even accept input from the remote control for accepting or rejecting calls.
That's in addition to the usual stuff that Asterisk can do, like handle your own voicemail, route calls to your cell phone when you don't pick up, and route calls based on the caller ID of the person calling.