You can host on Xlink Kai without a jtag, however anyone joining your game must have a jtagged console otherwise they will get booted for having a ping over 30ms. Its possible to remove the 30ms ping restriction on Jtagged consoles.
Thanks For This I Really Wish To Get Back To Gaming Soon
Which service do people use the most these days? I have mainly used Xlink Kai myself.
Drop xlink kai, get XBSlink XBSlink Download – XBSlink – XBox360 & PS3/2 System Link Proxy
It's far more stable, you direct connect so no latency added from random Xlink servers, it does have a "Cloud" option which publicly lists hosted rooms, and it's picking up rapidly for 360 and PS3.

so with these alternatives to live, is it worth paying extra for an unbanned jtag or not... I don't see the point as both can't go on live now. So you can only use the alternatives... Are there any advantages to buying an unbanned jtag?
Team XLink released a new version of the XLink Kai Engine, their global gaming network (that allows you to play system-link enabled games (incl. Xbox and Xbox360) online for free):
What's new/fixed:
* Added support for new Xbox 360 System Link game protocols
hi ive tried this and it says it cant run because of pssdk file? so im a little lost here.. any help would be great.
.You need to run XLink under Windows XP Service Pack 2 compatibility and enable Run As Administrator. For better reference look at the image below!