Working with FeatureCollections in the ArcGIS API for JavaScript provides some flexibility in what data you can provide as well as how you can update that data.
There's a demo in the docs that demonstrates how you might do this.
In this demo, I cover how you can take a FeatureService of GPS data and replay the dataset in your map rather than just display all the GPS data at once.
You can find the source code for the sample used here.
For more GeoDev tips and tricks, check out my blog!
