I'm a bit more bold with lack of security measures for now on my ipad and use hotel wifi and other open wifi assess points moreso than I have with my windows laptop.
I have verizon htc TP2 which is a windows Mobile 6.1 PDA and use winmobile wifi router app that works extremely well. Tried others with poor results. With this one I can connect to ipad and my laptop at the same time. Downside is it really sucks battery power so I have to connect to power or quickly drain the battery.
For Android tethering, check with Rockymtnhigh as I believe he tethers to his laptop. He doesn't have an ipad but that shouldn't matter.
Verizon also has their own software for tethering but they only support certain phones and they charge a monthly rent fee for it's use. You are not required to use it but they won't help you with third party software.
Good luck, tethering is fun.
