There is a lot of academic work related to these topics:

FOAF – Friend of a Friend [1]
FOAF is the semantic web ontology that describes ‘who knows who’.
This could potentially be useful in our project as we are inviting people from various social networks, and also no social networks. FOAF could be used in the following ways:

• Inviting people by URI
• Like facebook events list out all of your friends as potential ‘invitees’, FOAF could be used to also list out the URI’s of people the event coordinator knows.
• When it comes to the intelligent travel suggestions; FOAF could be used to align people who know each other into taxi/train groups.
• Link together who knows who from different social networks.

Distributed Semantic Social Networks [2]
Our idea is not the first to address the issue of breaching the divide between different social networks. In 2011 Android created a mobile application to try and connect people from different social networks [2]. The Android Semantic Web Core Library and WebID content provider for Android were created to work in harmony to produce a distributed semantic social network for android mobile users. Building upon the FOAF suggestions from above, these libraries did indeed use FOAF to link together participants. It also used WebID to link together users from a number of different social networking applications. Users could use their WebID account to link together their skype, google plus accounts to a single WebID thus making a single login that contained unified information about an individual. This shows that there is clearly a need to unify this information; and whilst our application isn’t centered around this point, it is aiming to unite people across the borders of different social networks (and unlike existing applications) also looks to include people who aren’t part of a social network.

Semantic Web Services [3]
McIlraith, Cao Son, and Zeng float the idea of Automated Semantic Web Services for travel in their paper ‘Semantic Web Services’ where users could ask for things such as “Make the travel arrangements for my conference”. This shows that people have considered using the Semantic Web to create intelligent services such as sorting out travel arrangements. However, this doesn’t have the inclusive features of our idea as it doesn’t facilitate a group of people all trying to get to the same place from different start points.

Similar Systems
There are some systems out there for both intelligent travel planning and event planning:

1. Intelligent Travel Planning (ITP) [4]  – A travel planner which allows the user to set both their travel and accommodation preferences and the system will for example organise their travel from the UK to Bermuda by their preferred method (e.g Flights/Taxis) and book them a hotel. However it does not seem to be linked to specific events, and like all of the other systems is lacking the facilities to do this for a group.
2. Location Based Event Planner [5] – This made use of the ability to track other peoples phones using GPS if permitted to schedule events in two different ways: firstly specific events, and secondly spontaneous events based around users proximity to each other. This is a pretty neat application and does look to break down boundaries of not having to belong to a specific social networking group to belong.

Conclusion
There has been academic work done around different elements of our system: distributed social networks and an intelligent travel organiser. However, so far I have yet to find a system that does both in the same way that we plan to. Therefore it seems like hopefully we have stumbled upon a unique idea; or at least one that isn’t obviously too similar to anything else.

References
[1] http://www.foaf-project.org/.
[2] S. Tramp, P. Frischmuth, N. Arndt, T. Ermilov, and S. Auer. Weaving a Distributed, Semantic Social Net- work for Mobile Users. In 8th Extended Semantic Web Conference on the Semantic Web: Research and Applica- tions, volume Part I, pages 200–214, Berlin, Heidelberg, 2011. ESWC’11, Spinger-Verlag.
[3] Sheila A McIlraith, Tran Cao Son, and Honglei Zeng. Semantic web services. IEEE intelligent systems, 16(2):46–53, 2001.
[4]  Zachary Pousman, Giovanni Iachello, Rachel Fithian, Jehan Moghazy, and John Stasko. Design iterations for a location-aware event planner. Personal and Ubiquitous Com- puting, 8(2):117–125, 2004.
[5]  David Camacho, Daniel Borrajo, and Jose M Molina. Intelligent travel planning: a mul- tiagent planning system to solve web problems in the e-tourism domain. Autonomous agents and multi-agent systems, 4(4):387–392, 2001.