Should I get a new backup phone?

I used to have a backup phone in the past, just in case my current heavy duty phone breaks down. it was my W700i which made me owned my very first mobile phone and W910i, which was my longest phone ever to be with me at all times. Now W995 has taken the lead and all this thinking leads me nowhere.. Technology evolves real fast nowadays. Touchscreen phones are really popular nowadays, three years back it was not ruling the mobile industries yet, but now i'm sure you have one in your hands. And back to the main point, should I get a touchscreen phone as a backup phone or just a simple phone which we can text and call.. Actually i'm all set to get the best in design phone currently from Sony Ericsson which has low SAR value. In case, some of you may not know what's SAR is: Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field. All mobile phones have different values of SAR. Do not take a phone which has more than 1.60W/kg averaged over 10 g of tissue. Its rather harmful to your head when you make calls. Alternatively, you should use a earpiece to make the call, to reduce harmful effects to your body tissue which leads to skin cancer or brain damaged. Currently, T707 has a healthy SAR value of 0.62W/kg compared to iPhone 3G, 1.38W/kg.

should I get the Sony Ericsson T707 as my backup phone, it's very worth it. Its retail price is at S$288 at the Sony Style Singapore.