free way to stream to ipod touch without jailbreaking
There are a lot of options for this. The easiest ones use a native iPhone application that will cost you a small amount (usually around $2.99 on the app store). But you asked for a free solution so I'll start with that:
Free Option
Jackson Chung over at Makeuseof.com has written a detailed explanation of how to stream your iTunes music library to your iPhone/iPod/iPad for free. It wont be the greatest experience so I'm going to include a couple of the paid options below as well.
Paid Options
These two options use a iOS application to enable the streaming:
StreamToMe — $2.99 on the App Store

Use StreamToMe on your iPhone, iPod Touch or iPad to play video,
music and photo files streamed over WiFi or 3G from your Mac or
Windows PC. No prior conversion or syncing required (huge number of
formats supported without conversion) just tap the file and it plays.

AirPhones — $2.99 on the App Store

AirPhones sends the audio from your computer to your iPhone or iPad
with virtually No Latency. Perfect for wireless, synched audio.


Finally, this option does not require an application installed on your machine as it runs a small server that is accessible via an iOS-friendly web interface on your device.
Remote Buddy — €19.99 on their website

The most powerful remote control solution for the Mac®. Control more
than 100 applications, virtual keyboard and mouse, presentations,
media center software and important system settings right from your
iPhone™, iPod® Touch, your Apple® Remote or one of the many other
remote controls supported by Remote Buddy!