The GPS of the protein world, signal peptides direct proteins to their correct destinations within the cell. (Take a left at the mitochondrion, then proceed for five microns.) With SPdb, researchers from the National University of Singapore and Macquarie University in Australia provide a way for scientists to navigate the myriad signal peptides found in archaea, prokaryotes, eukaryotes, and viruses. Integrating information derived from two databases, the EMBL nucleotide sequence database and the Swiss-Prot protein sequence database, SPdb currently contains a whopping 27,433 entries. Among those entries, you can search by organism or broad data group (such as eukaryotes), and you can choose to filter the results to include only those entries that have been experimentally verified. (Sadly, though, this limits you to only 9.2% of the sequences in the database.) So go ahead and maneuver yourself over to this great database—no GPS or driving directions required!