Dear Aunt TUAW,
One iMessage "feature" is that messaging can be started on one device and picked up from another device, like from iPhone to iPad. My wife and I share an iTunes account so that we don't have to pay for apps twice, or worry about signing into different accounts. Will sharing an iTunes account across two iPhones mess with our ability to text to each other with iMessage? Thanks!
Your loving nephew,
Fear not. Your store account is distinct from your iMessages account. You can create separate Apple IDs for iMessage so you and your wife can pseudo-text back and forth.
You will, however, require two email addresses. Select Settings > Messages > Receive At and create a new Apple ID specific to those addresses.