One of the greatest pleasures of my career to date has been attending conferences overseas. If, like me, you research contemporary British history and study/work in the UK, then the chances of heading off somewhere exotic/interesting/warm to hit the archives are usually limited. I chose particularly badly on the 'reasons to travel for research' front by working on East London, where I also happened to live and work part-time. So I needed nothing more than a zone 1-3 travelcard in order to get my research done. In terms of meeting people from around the world in my field, I was spoilt by a) doing my PhD at the IHR where most people rock up to at some point and b) working at one of the archives my fellow specialists would travel to.
However, whilst it's very easy to have everyone come to you, there are many, many good reasons why you should get to an overseas conference at least once in your PhD studies, beyond the getting more stamps in your passport and it looking good on your CV. Some studentships - usually research council ones - will offer a multi-purpose research support grant that can be used for travel to conferences, and if you are in this position, then you should seriously consider using your grant for this. If you aren't this lucky, then it is more than worth making an application to schemes such as the Royal Historical Society's postgraduate support scheme. Money might also be forthcoming from other sources, including alumni funds from your university or school, local trust funds and the like. The IHR's Grants in History is always worth a look, too. The conference you are attending may also offer to pay some or all of your costs.
I've had a number of trips for conferences outside the UK: two to the University of Groningen, in the Netherlands. The first trip was arranged by my university, and was supported by a British Academy grant, back in 2003. The second resulted in my gaining one of my first publications in an edited collection. I also got to go to Japan to attend an academic conference, although this was through my paid work rather than through academic channels. The Social History Society periodically holds its annual conference outside the UK, and I've been lucky enough to get to Dublin (2005) and Rotterdam (2008). I am involved with the British Scholar conference held by the University of Texas at Austin, which is a thoroughly enjoyable conference, having been to it twice.
So what did I gain from my travels? Well, the EU conferences left no evidence on my passport, if the Japanese and US jaunts have. On the most basic level, it's been an opportunity to travel and to experience something out of the norm. But it also opens your eyes to the ways in which universities and research work beyond the UK, which are the kinds of things you discover through observation and through small talk. I'll tackle the first point first. If you have spent all of your educational and working life in Britain, it's easy to forget that the world simply operates in different ways. For a start, British degrees - indeed secondary schooling - is relatively unusual in offering early specialisation. Thus British graduates fresh from school are generally let loose on industry at the ages of 21/22 - or they can begin an MA at an equally tender age, before starting a PhD a year later. For those who have straightforward (or at least relatively straightforward - I'm not alone in having a segue into 'real life' before doing my PhD) routes through to their PhD, the average age at completion is 25-28 or so. Compare this with the US where a four year degree programme with specialisation in the later stages leads to a longer postgraduate programme, often interrupted by the pressures of funding studies through taking on paid work. PhDs in the Netherlands are examined in public... so rather than sitting there in front of your examiners and possibly your supervisor, trying to avoid puking, you could be standing up in front of an audience, defending your thesis in public, trying to avoid puking. These are a couple of examples that would suggest that the experience of doing a PhD - and later working as an academic - is not as universal as we may initially think. It's a useful means of starting a discussion about what it is we do prepare our postgraduate students for, and whether there is anything to be learned by doing or examining a PhD a different way.
The other way in which getting out of the UK and out to a conference is in terms of the way in which it changes your perspective on your subject. It's not just the exposure to a different narrative that counts. It's also an understanding of how not being British, how not living and working in the UK, for example, might literally shape the way in which you come to your work. How do you work your research questions with the practicalities of archival research? How might the training offered where you did your PhD take you in other directions to that of a British-trained PhD student? These are refreshing and important points, at least to think about. In short, whether it is the way a conference is organised, the experiences that your colleagues have had, the take they have on your topic, all raise questions about the global nature of academia and how postgraduates fit into this.
So, in my view, it's worth making the effort to apply to overseas conferences and to work on getting the funds together. Granted, options involving sea travel and Eurostar may become more important if the Icelandic volcano continues to spew ash into the atmosphere, but it's still worth it...