Access and modify files on the SD card of my mobile using WIFI tethering I am looking for an application for my Android 2.3.5 Sony Xperia X10i.

I want an app that will mount my phone on my hot spot as eg: http://192.36.02.08 , which will have both download and upload functions. 

I want this so that I can quickly transfer files from my computer to my mobile in a hurry, as I have found out that WiFi speeds for file transfers are much faster than that of an USB cable.

Are there any apps that can do it?

I appreciate any help.
You've got quite a few Apps that can do it:

Wifi File Explorer

Wifi File Transfer

3rd: WifiDroid, it doesn't let me post more than two links because of my reputation, but you can search in google.

4th: AirDroid, it allows you to transfer anything, and even control your phone with it.

I've used the first too, both free and pro versions, i like the 2nd more, the 3rd i never used.