Youresam has just released the latest version of netlib, a development library that makes the process utilizing the PSP's infrastructure mode easier for homebrew developers. You can now also use "netcall" to call someone via your PSP, and email libraries have been added. This is fantastic news, and should hopefully open the gates to awesome homebrew infrastructure applications and games in the future.
Check out more info about this new networking development library
here.
Download netlib v1.3 from PSP 3D
here.