Switzerland is well known for its banking system. Union des Banques Suisses (UBS) is one of the biggest international group in financial activities.
But the most well known bank in Geneva is of course the BCGE (Banque Cantonale de Genève) that provides a large offer of services to its clients (standard account, investments, mortgages...).
You can get a debit card EC (the cheque is not really used in Switzerland) that you will be able to use to pay for your shopping, or to withdraw money from cash machines bancomats. Some bancomats give also euro notes.
Invoices can be paid directly with the BVRB (bulletin de versement bancaire).
For tourist purchases in Switzerland, you can also pay with Reka cheques [http://www.reka.ch]. They can be purchase from the Coop supermarkets with a discount of 3% (only if you show a Supercard - Coop fidelity card) and through 2700 employers and unions that gives up to 20% discount. You can also get the Reka cheques by excanging points earned with your UBS account.
You can pay with the cheques in some 6900 companies in the tourist business and in Swiss transport stations (hotels, restaurants, travels, transports,...etc).