The orbital data for a satellite changes with time. While a given set of data is accurate for at least a few weeks to a couple of months for low-accuracy naked-eye observation, you will eventually have to update it. Fortunately, there are quite a few sources on the web for up-to-data orbital elements.
PocketSat reads data stored in the popular TLE (Two Line Element) text format, and PocketSat3 can import the data directly from the web. Previous versions of PocketSat require that you download the data and transfer it to your device. See the documentation for your version for details.
Satellite TLE data sources:
celestrak.com - This site, run by Dr. T.S. Kelso, is the single best source for satellite data on the web. Under "current data" are dozens of sets of data, grouped by satellite purpose or type. For PocketSat3 simply copy a link from the website into a new "Date Source" and you can import it. For other versions check out the "Space Track TLE Retriever" application which manages TLE downloads and will convert the data into the format needed by Palm devices.
AMSAT.org - AMSAT maintains current data sets for satellites of interest to radio amateurs under the heading "Keps". Be sure to point to the "bare 2 line" date file unless, of course, you need Palm-formatted data, which is also available.
space-track.org - this is the original source for almost all of the TLEs you will find. Run by the US government, it requires that you register and agree to some terms in order to access the data. Note that at the moment PocketSat3 is unable to directly download data from space-track because of the login procedure.
PalmOS PDB Generator Tool:
Users of PocketSat and PocketSat+ for PalmOS devices need orbital data that has been converted into a PalmOS database (.pdb) file. This Online Tool will create PDB files from text TLE data.