Inevitably, a file or program you need on the computer you're using will be on the computer at the office or home where you're not.
You've no doubt heard of "go to my pc" through its heavy advertising campaign.
It lets you log on to your home or office computer remotely.
You can access both Macs and PCs and transfer files, run programs, run it just like you're sitting in front of it even if you're across the country.
There's a free 30 day trial, but after that it costs a lot. $20 a month, $180 a year.
There are other remote access program that are less known, but contain many of the same features and they're a lot cheaper.
Logmein has several versions available but you can buy a year's subscription for $70.
It also has a totally free service I use to control some remote weather cameras on my home pc.
The free version won't let me drag and drop files, but I can run my home pc and close programs and run it like I was right there.
But what I like most about it is a $29 application that lets me run my home computer right from my iPhone...from anywhere. Anytime. Remote access...I like it. A lot.
To get these links: