TAAMINATOR  Audio Hijack Pro is versatile, reliable and stable, and quickly customizable. Rogue Amoeba tech support is the best in the business.

Use:

I mostly use AHP to time-shift internet streams.

Versatile:

AHP allows you to record anything you can hear on your Mac into a broad spectrum of user-customizeable formats.

Install SoundFlower (free) to AHP and you can divert multiple simultaneous inputs to multiple simultaneous outputs.

I use AHP to time shift, but I also use it as an tuner-timer. When scheduled, AHP hijacks a stream and sends it to Airfoil. Airfoil sends the stream to Apple Airport Express-hosted speakers throughout the house, garage, and patio. (AHP is so robust that you can configure AHP differently: AHP can use iTunes to send the stream to Airport Expresses directly.)

AHP continues to spirit of Apple: AHP can do anything!

Reliable and Stable:

AHP is a "set and forget" application. You can set AHP to record and leave for weeks. The only worry is filling up your hard drive.

AHP never crashes of its own free will. Once or twice a year, Mac OS X may crash AHP, but the AHP Schedule Helper restarts AHP.

From nothing to scheduled in 60 seconds or less:

My friend announced that he will play a special, radio program on one day. I wanted to record it. I selected AHP2, added a new session (I should have copied a previous session.), entered the URL, selected the source (iTunes), added date and time and length, and AHP2 was ready. I tested it. Perfect. I selected the recording format to AAC. I need to add the tags, but, hey, that's trivial.

Tech Support:

Rogue Amoeba's tech support rivals or soundly beats the best in the business.

I had trouble with audio lag in an older Mac (skipping). Even though the problem was not theirs, RA was extremely courteous and helpful and developed a solution that I still use.

Summary:

AHP2 is amazingly robust, and, absolutely, positively indispensible! And, you can go from nothing to scheduled in 60 seconds or less.   
(Version 2.9.6)

LITTLE NEPHEW  Not to slam HEAR, SRS iWow, or Gen Audio SoundExpander, but after months of promising 10.6.2 compatibility, NOTHING. Audio Hijack Pro does what the others (used to do), and so much more. You can hijack iTunes, customize the effects with DOZENS of parameters, name it, and save your settings as an .fxpatch. You can do this with ANY audio, and create custom patches for each one - iTunes, games, etc. You're not limited to the limited presets the others offer.

All this in addition to the array of other functions the app provides. Rogue is always on top of OS changes, and ko's the competition even when it works. Gotta give it a try!  
(Version 2.9.6)

AVIDMCUSER  Agreed! Rogue Amoeba Rocks! I have purchased Audio Hijack Pro as well as Nicecast. Both very useful with many great features and superbly crafted. Although I am still having some issues with Snow Leopard 10.6.1 with various apps, I am hoping an update from Apple will resolve any crackeling I am getting through 'pitch' filter using external iSight mic input.

Just curious, this update is listed for the 21 Oct. but I have had this version for some time now self updated. Is it a different build?  
(Version 2.9.5)

DENNYMOREJ  Huge fan, love these folks. Great product, thoughtful upgrades. Easy to use. They care about their customers, also evident with that great gift of Pulsar (free to Audio Hijack Pro users) a huge plus for us Sirius listeners using Snow Lep.   
(Version 2.9.5)

SUPERMAN S  software that I used every day, excellent, I recommend  
(Version 2.9.4)

LEONCAHUN  On my MBP, OS X 10.5.7, the updated Soundflower 1.5.1 kext (Kernel Extension, System Extension), which comes with AHP 2.9.3, did not install successfully; after the first restart the OS claimed that the kext was disabled and had to be de-, or re-installed. I de-installed.

Apparently, there is a compatibility issue with Soundflower 1.5.1 and, at least, 10.5.7.

Earlier versions of Soundflower did not trouble my OS installation. YMMV.  
(Version 2.9.3)

PAT320  Tiger users: "Good Bye!".

Now requiert Leopard.  
(Version 2.9.3)

AVIDMCUSER  My previous comment was supposed to be placed below D Point's comment. I did click the reply under his post.

Anyway, just wanted so say a big THANKS to Roque Ameoba for your fast efforts to support us on Snow Leopard with Audio Hijack Pro. A fantastic app that I find hard to live without. Well done!!! Money well spent!!! PS Same goes for Nicecast.  
(Version 2.9.3)

AVIDMCUSER  Sure got you guys thinking about Snow Tape didn't it? LOL  
(Version 2.9.3)

STEVEN GOODHEART  Huzzah! Full Snow Leopard compatibility and Instant Hijacking is back!

This is one my favorite programs, and one of its simplest built-in features -- the 10-Band EQ that you can add to any program you hijack -- adds so much richness and depth to the the music I play in iTunes, or from LastFM in my browser. YMMV, but I found AudioHijack's built-in EQ (which has pre-sets) to be every bit as good as SRS iWow iTunes audio enhancer plug-in and it has much less of a performance hit.

This is a five-star program with excellent tech support and at a great price. Can't recommend it enough.  
(Version 2.9.3)