At the risk of sounding like a reckless spammer, I recommend the company I work for: FreshBooks.

We have more than just time tracking and invoicing/billing. Including estimates, simple support tickets, document sharing, expense tracking, contractors.

We do not do full accounting or payroll. If you need those capabilities I recommend either checking out our competitor Xero, or checking out an accounting package that integrates with us.

I'm on support today if you want a walk though or something. Toll Free (North America): 1-866-303-6061 Toll Free (UK): 0808-101-3408 Just ask for Zach. http://www.freshbooks.com/our-team.php#zach