For researchers out there who study Arabidopsis protein phosphorylation, the PhosPhAt database is an invaluable resource. PhosPhAt is a searchable database of—you guessed it—phosphorylation sites, as identified through a number of mass spectrometry experiments. At present, PhosPhAt includes experimental data from 24 published studies, so there is a lot of depth to the database. The database itself is accessed via a Java application (compatible with Windows, Mac, and Linux), and is searchable by protein (AGI) codes, peptide sequences, or protein descriptions. In addition to the basic phosphorylation site search, users can also search for kinase-target interactions or use the phosphorylation site predictor feature. The website is nicely organized and the Java app runs smoothly. PhosPhAt is a very nice resource for plant biochemists.