GoingVirtual.wordpress.com has posted a great step by step How-To for configuring the software iSCSI initiator in vSphere 4 with multiple paths. The is a huge reason to go to vSphere 4 from ESX 3.x since ESX 3.x did not support multiple paths per target.
The How-To can be found here:
http://goingvirtual.wordpress.com/2009/07/17/vsphere-4-0-with-software-iscsi-and-2-paths/
Hope it helps!
Lewan IT Solutions Technical Blog 
I don’t know If I said it already but …Cool site, love the info. I do a lot of research online on a daily basis and for the most part, people lack substance but, I just wanted to make a quick comment to say I’m glad I found your blog. Thanks, 🙂
A definite great read..Jim Bean
Hey, I found your blog in a new directory of blogs. I dont know how your blog came up, must have been a typo, anyway cool blog, I bookmarked you. 🙂 🙂
thanks for the mention.
Brian
(goingvirtual)