Hanover is normally very safe. Before and after a soccer match there might be quite a few drunken people around, especially in the central station, but there always are police patrolling.
In Kröpcke you may get asked for money by the homeless. Pickpockets may act in crowded area such as inside the trams during a big exhibition.
wlan connection
For those of you with portable computers, WLAN connection is available inside the Central Station. There are also several cafes providing WLAN connection free of charge:
Art Oase, Egerstorffstr. 12
Depot Cafe & Bar, Kramerstr. 10
Viva Gastronomie, Vahrenwalderstr. 92
Cafe Extrablatt, Friesenstr. 14
When you supply a german mobile number, each McDonald's restaurant in Hanover provides one hour of free Wifi. The phone number is not used for advertising.
laundromat
One laundromat can be found in Oesterleystr. on Sudstadt.
There is an unattended laundromat on Engelbosteler Damm 75, near the "Kopernikusstrasse" tram stop. One machine is about ⬠3,50 including detergent. Open till 11PM every day.
Another laundromat is at Deisterstrasse best walk from the "Schwarzer Baer" tram stop. Same proprietor as the place on Engelbosteler Damm, so same prices&conditions.
For a laundromat with a twist, try Waschweiber Salon & Bar, Limmerstr.1, +49-511-1237696. Mon-Fri: WASCHsalon 11AM-9PM, Bar 11AM-1AM, Sat: WASCHsalon 9AM-9PM, Bar 11AM-1AM. Last time to start the machines is 9PM.