WinPhone7 - Save more than one number for texting
In Windows Phone 7 for now [7.0.7004.0] you can text only mobile number.
if you have and existing contacts with extra mobile numbers - they are are stored as home > you just cannot send a text to home number. :(
Here is the workaround >
Make one more contact with same name and add that extra mobile number here and then merge the contact - like >
Now you can text both the mobile numbers :)