I run an in-house creative department of 15 designers, production
artists, etc for a large corporation.  We need software that helps us
manage and collaborate on projects.  We also need to give access to
our customers so that they can review and approve our work.  Ideally,
the software needs to be web based.  I've looked at products like
Clients and Profits and Creative Manager, but these software packages
tend to focus more on accounting (i.e. billing for an ad agency) than
collaboration.  Also, these seem to be very small software companies
(2-5 people).  I'd rather buy from a larger company that will still be
around 3 years from now.  Does any solution exist that meets all my
criteria?

I manage the creative services department at Monster and have recently
selected RoboHead as our creative project management software
application. RoboHead allows everyone involved with a creative project
to see exactly what they need to see--and only what they need to see.
From project management capability to pull reports on various aspects
of a project or a resource (staff availability, amount of time spent
on a project vs. estimated for that work, number and calendar span of
projects by client, and on and on), to creative collaborators ability
to discuss project requirements, post work for internal and/or client
review, client capability to comment specifically on work in progress,
documentation on all of the above, and searchable archive capability
for completed work, RoboHead really is a comprehensive solution. The
online accessibility makes it possible for users in disparate
locations to easily participate in the creative project lifecycle.
It's clear that people truly involved in creative project management
developed this solution, and have given it a great deal of thought. I
am managing many projects with RoboHead now, some of which are pretty
simple with few components, others extremely complex, with multiple
moving pieces. I have yet to run into a problem that can't be solved
by using RoboHead slightly differently. So, if that's not enough, the
RoboHead staff at Aquent are dedicated, completely available, willing
to work with their client's specific needs, flexible, intelligent,
enthusiastic. They've made easy a complex implementation of this
application at Monster by suggesting a roll-out plan that has allowed
us to gradually bring a large number of staff on board relatively
painlessly. They worked closely with us to understand our specific
needs and to tailor a program that would work for us. And even now
that we're running with it, they are still available to me for
troubleshooting problems and suggesting alternatives for resolving
them. For all this, you would think it's probably really expensive.
It's not.

eroom is another option.  Now part of a large outfit after being
bought out.  I've used them to manage technology projects.  No
complaints so far.  www.eroom.com

We host software projects at http://www.Projxpert.com/ but the
software is quite flexible. It allows your team to communicate and
collaborate around a project, no matter where they are.

You get:
 o) your own version control repository which is like having a shared
hard drive which remembers every change to every file.
 o) an issue tracker  
 o) discussion forums

The software is aimed at software developers but depending on your
requirements it could provide what your after.

s.

There's a web based solution called ProWorkflow - www.proworkflow.com.
It's great and has been built by a team of designers with creative
agency experience, so is built from the ground up to work the way we
do...
ProWorkflow manages timesheets, projects, tasks, invoices, quotes etc.
They have free trial accounts, and a subscription model so for a team
of 15 - it's affordable.
Also, the company offer fantastic support, and have a happy, solid
team. We use ProWorkflow to collaborate with our 4x person design team
and have staff in different locations up the country. It manages it
really well - we all know where everything is at. The web address is
www.proworkflow.com

Try www.kiwimanager.com. It is designed with creative professionals in
mind and th features you need (approvals, reviews, mockups) are
already built-in.