I know that a Cisco VPN profile can be setup on iPhones. If I was able to get that setup on the phone, would it be possible to map a network drive to the iPhone?
Would want to map it to a folder on Windows Server 2003.
The app NetPortal can do this. I've got it set on my non-jail broken phone. I connect the native VPN to the office network and I can browse the network. You don't map a drive just have "favourites" in the application and then open them up.
Theoretically yes, iphones are just very locked-down BSD-like machines, when I was messing about with jail-breaking mine I found it very easy to get SSH working at which point it would be possible to install all manner of fairly standard *nix code, including a SAMBA client and any other tools. It'll take you a fair bit of faffing about and obviously you do this at your own disk but I think it's eminently possible yes.
I do have to ask the question why?
I don't think it is - not as Apple ship it anyway - aside from anything else, the iphone doesn't make file systems available to the end user.