So I have an old Blackberry curve 8330, my battery is about 2 years old and only lasts a day. I was wondering if buying another battery will fix this, it's really annoying... Lasts about 24hours on average.
Also, I don't have service in my house (fuckin black zone...), so I was wondering if the fact that it's constantly looking for service in my house affects the battery life.

yeah, constantly looking for service will sap battery life
a new battery would improve life roughly thirty percent I think
IIRC, lithium batteries lose roughly ten to twenty percent capacity per year

3 bucks, worth every penny. Free shipping too.

http://cgi.eebay.com/BlackBerry-C-S2-Curve-8300-8310-8320-8330-CS2-Battery-/140515520156?pt=PDA_Accessories&hash=item20b760ae9c

Simply put your phone (assuming it has this feature) into airplane mode.

What this does it stops your phone from trying to obtain service.

I use it during class cause there's also no service at my school, it helps save battery life and prevents me from having to turn it off everyday.

Hope this helps, cheers.