There is Tweak available in Cydia for Jailbroken iPhones that let you install icons for Compose New sms/email. This tweak is good for composing email & sms quickly from home screen.
After installing this Tweak there is no Options to Configure. Just tap the Email or SMS icon to get into compose Window quickly.
You can download this Tweak for Jailbroken iPhones from Cydia Big boss Repository