I have have to create a custom workflow for SharePoint 2010, however we are blocked from using Designer, and have MS Office 2007 not 2010. Is there a way to create a custom workflow any other way? Can it be done in Visio 2007 or InfoPath 2007?
No custom workflows cannot be deployed/installed to SharePoint using Visio or InfoPath. If you have already created reusable workflow using SharePoint designer, you can save it as a template, go to Site Assets library and save it as a WSP package.
The WSP can then be installed as a Farm or Sandboxed solution in the target environment.