Datasets for using ML algorithms

Hi,

I've worked through much of the machine learning course that is on Coursera from Andrew Ng. What I would like is the opportunity to play around with some of these algorithms in practice, for example, support vector machines, clustering, neural networks.

I am quite experienced in R and have experience working mainly with regressions and time series forecasting, so I shouldn't have much problem figuring out the mechanics of doing it, I just need the datasets. Can anyone guide me to some useful datasets online that would be interesting for these types of algorithms? Thanks.