There have been many tweaks and applications for this. For example: Bite SMS has the ability, but this tweak is suitable for all those users who prefer to use Native messages app instead of any 3rd Party application. However, another similar tweak is Copic which allows users to import contacts photos to different applications including text messages. But it will cost you $1.29.
According to developer of xMessages;
Adds options to Messages app. It integrates contact photos and adds timestamps for all messages. Either feature can be toggled from the Settings application under xMessages
To get this tweak, Open up Cydia and search for xMessages. Click on it and install it. To switch off the features of this tweak, go to settings and you can toggled both features from there.