I started using Creative Pro Office for 2 of my businesses (mainly for my consulting business with 3 partners, my main source of income) a short while back and have to post here to recommend it to others.
It's a free online suite of services to do client & project management and invoicing and simple accounting. Give it a try:
Project Management, Time Tracking, Invoicing, Quotes : CreativePro Office
(note: it's free, and I don't get anything from recommending it aside from letting more people know about this resource)
Only thing so far I don't like is part of the invoicing: I wish they would have item/service lists pre-done to select in a drop down instead of having to enter descriptions each time. To get around this I made a note[ad sheet with my items/services to cut and paste.