Working remotely is definitely an enormous adjustment to the regular office grind. I'm not talking about just being in a remote office, I mean going solo and working by yourself, with only electronic communication at your disposal.
Working solo deprives one (to a certain extent) of the ability to bounce ideas off other people. There is undeniable benefit in getting other opinions on a matter, even if they are dead wrong*.
When you are physically separated from your colleagues (in my case a 2hr flight), you tend to depend a lot more on other resources and your own judgment.
Conveying a technical idea verbally takes a few minutes. Doing it over a tool like gchat is arduous and often leads to frustration and misunderstandings. Nowadays, rather than quickly running an idea past a co-worker, I would now Google it, see if anyone else has had a similar thought. Or I would simply just dive in and do it, see how it turns out and then either keep it or chuck it.
I think there are two key ingredients to making a success of telecommuting: discipline and communication.
You have to constantly check yourself. Have I wasted time investigating this idea? Is this taking longer than it should ? Am I understanding this correctly? There is the ever present danger of just buggering off on a tangent, never to be heard from again.
Having people on the far side who are available and reachable and (more importantly approachable) is critical. I can't imagine my work day without at least a few quick checks like "hey, is this what you had in mind?" or "what the hell are you talking about in that bug report?". You need people on the other end of the line you can converse with over an instant messenger. Email also works, but the hassle of writing and email to just fire of a short question is not justified.
The last thing you want is your communication to always be rigid and formal. You need an easy way to interact with people immediately, the same as shouting across the room or darkening their door for a quick chat. Remeber, you are in the office, your just not in the office.
Also, keep people in the loop. I fire regular short progress update emails during the day. It gives people a handle on what happening, helps them manage their own expectations.
Tools of the trade
My instant messaging is overwhelmingly done in gchat, with a tiny portion on MSN. Most of my clients hosts their email with Google (something I heartily recommend, I do it for ShuntYard also), so everyone in the office is mostly available through gchat.
My email is exclusively done through GMail (private and work), so I have a central place to keep tabs on everything.
*I guess this relates to always running your plans for world domination past a 5 year old.