A new business contact sends you a sms and since you just met a few minutes ago, the sms shows up on your new Windows Phone 7 with the phone number displayed. Obvious, this is a new contact. So how do you go about adding the phone number to your contacts?
Simple, open the SMS you just received and tap on the phone number at the top of the screen and this brings up the unknown contact profile page. Tap the Save icon on the application bar and you will be presented with the Choose a contact screen. You have to choices here: (1) Search or (2) New Contact.
The option to search a contact lets you save the phone number to an existing contact. But this is not what we want here. Tap "New Contact". The phone number is automatically added to the phone field and you get to set the Phone number type. Save your changes by tapping the tick at the bottom of the screen and you're taken back to the standard Contact page where you'll be able to add a photo, name of the new contact, assign a ringtone or add an email address. Tap Save and the contact are added to your phone. One last thing, if you have more than just the default Windows Live account, you will be given the choice to select to which account to save your new contact. For that, tap that Account field.