Hello Guys. I am considering to buy a TP Tablet, as in my country the 3G version is unavailable I need to have a tethering functionality with my blackberry phone. Can anyone tell me if this is possible and what app works this connection ?

There may be some useful info on the following Blackberry support page's:
About using your smartphone as a tethered modem
Connect a computer to the Internet using a BlackBerry smartphone as a USB tethered modem

The OP suggestion goes to tether a blackberry phone with a blackberry tablet or a Laptop using BB's Desktop Manager. None of these are useful to connect a Thinkpad Tablet to the web using the blackberry phone as a modem. Sorry. Until now it seems to be an impossible task. I wonder if an andriod phone could tether to the Thinkpad Tablet as they bear the same android language..

Has anyone succeed navigating with the Thinkpad Tablet using an Android phone ?

Sorry did not realise the TP Tablet is an Android device - On my old HTC Desire Android there is an app called "WiFi Hotspot", I have not played around with it as yet - but according to the on-screen info >

Portable Wi-Fi Hotspot can share this phone's 3G internet connection with your PC via WiFi. After the Portable Wi-Fi Hotspot is started on this phone, your PC can connect to it and then start using the internet

This app does seem to be on most HTC Android devices and would seem to allow cross platform internet connection via WiFi from a 3G service.


Edit:
Can confirm this app works really well - have been able to setup a local WiFi hotspot (54Mbps) and share the 3G's internet connection with a couple of PC's & BB's as well as HTC mobiles - both standalone & simultaneously -

I tethered my Thinkpad Tablet with my Samsung Captivate the other day.

Worked just fine. I am running a custom ROM on my phone so I am curious of AT&T detected the tether or not.