On thing about growing a company quickly is you do get to feel the "growing pains". One of the biggest challenges for Offhollywood lately has been finding way to more effectively collaborate on projects and communicate within the company. We've been testing BASECAMP for the past month now and have now fully committed to using it to manage our projects and improve communications. Basecamp is a web based application by a company called 37signals - you can see a link to their blog Signal vs. Noise on my sidebar. You can manage to-do lists, time-track, and set milestones with little effort and also use permissioning to collaborate with selected staff, or everyone. One of my favorite features is that I can invite an OUTSIDE client or person into a project - they get a URL and a username/password - and they log into the project.
There's a few price points - we went for the MAX - which is $150 per month and gives you unlimited projects and clients and 50G of space for attached files. There is a plan for $49 a month as well which is locked to 35 active projects. For me - $37.50 a week for better communication and collaboration was a no brainer. There's a 30-day free trail - so check it out!