Several companies provide online services
NetSuite.com
Lawson, Oracle, and SAP provide some hosting options
Many others
Few companies use accounting systems in the cloud.
Security, privacy, and reliability concerns
Customization is needed in both cases and it can be expensive
Variable costs can be expensive over time
Browser-based approach is relatively new and mobile networking has been expensive and slow
CRM is popular online
Largely Salesforce.com
But if it is not integrated with the ERP it is largely contact management.