The following is a highlight of a competitive analysis I did earlier this year when I was involved in designing software that would allow remote research teams to work together. While software is still a long way from replacing all in-person collaboration it's becoming easier for remote or mobile workers to stay productive and communicative with their team. Certainly the tools we have available today are a vast improvement over what I used when I first tried telecommuting 12 years ago!
There are many articles out there covering similar if not exactly the same ground. Hopefully you will find some gems in mine.
GetSignOff Work with your clients. Getsignoff is best for web designers to help them manage client feedback http://designsignoff.com/get-signoff Goplan Online Manage your team's calendar (and sync it with your mobile devices, like your iPhone), assign tasks and tickets, manage files and assets and discuss in a centralized location. http://goplanapp.com/