One of the easiest and low-cost ways of getting your data online is by using GitHub. While mainly aimed for code, it can be used for other things as well.
A great feature is the rendering of .geojson files as maps automatically.
I have a .geojson file of a Trans-Siberian journey in WGS84 (currently the only supported projection). I copy and past this to gist.GitHub.com and name the file TransSiberianSimplified.geojson (I think lowercase is important in the file type). It is then automatically turned into a slippy map. This can then be embedded (for WordPress I have done this by creating a simple html page which simply contains the relevant script, and embedded it using an iframe plugin).