With the doorknob 'beeper' alarms, you can also buy the 'personal alarm' kind which have a strap and clip which can be used on say, a handbag ... you hold the strap in your hand so if someone snatches your bag suddenly, they find themselves running away carrying the bag AND a bloody loud bleeper -give them quite a shock I would think!!
The model I used to have also had an attachment where you hung it on the door handle and placed a pronged end in between the door and the jamb... again, if door is opened the alarm went off... I think I got it from the RAC as part of my car insurance...
