I rather think I might have already talked briefly about this early blossomer - Prunus cerasifera 'Nigra', the Black Cherry Plum.
It does blossom ridiculously early in the year, with many thousands of delicate pink/white flowers that are often mistaken for Blackthorn.
I did see a bush of Cherry Plum flower almost a month ago now (or at least a few branches of it were flowering, anyhoo), but now all the local trees are exploding in this pink-white colour.
Although the species is a little, how can I put it.... er.... cultivated? Urban? I still think its very nice to see. It'll do me, anyway, Tommy.
Click either image to enlarge (both are now also in the "New Warren" even larger still).