More often than not my expenses are related to a specific task, but there are times when I need to keep track of general expenses. I may work for 3 clients/projects in the same day and want to track travel expenses for the day. I'm an independent contractor so they're not billable, but I track my travel for tax purposes. The only workaround I've used so far is to create a dummy project and to add a task for the day in order to post the expenses. Sometimes an expense IS related to a task so I'd add it to the task, but then it's difficult to get an export of all expenses for a month across multiple projects.
Overall I'm really happy with the app - and I've tried a dozen - but I can't get a good workflow going for my expenses. I'm open to suggestions.