I don't know of any shared hosts that will allow user-submitted modules to be included in their distributions. It causes many concerns for hosts (security, stability, general usage and such). So I can't see any host to use your own module.
One thing you could do is get a VPS and do it yourself. It's less-costly than a dedicated server; however, you share resources with the other VPSes that are on the same machine.
I do know of an alternative (that's about as affordable as a high-end shared host) which is from Flosoft.biz. They're calling it FlexServ which is a dedicated box with shared space. I'm not promoting them, but without a VPS or Dedicated or Flosoft.biz's FlexServ, you can't get your module loaded.
PHP doesn't allow multiple spots to look in for modules, you can only have one. So your module would be available to any script that uses that version of PHP.
Hope this helps, sorry you didn't get the answer you wanted.
With respect to your friend running it in a shared server with "./" as the php.ini value, that's just saying that the extension directory is the current php.ini directory. Nothing to do with the current scripts directory. So he could be loading it via [man]dl/man but most good php hosts disable this for security reasons.