This is without all the complicated web-of-trust stuff, displays just whether the signature was correct, and a list of files where you have seen the same signature before.
More details in the README.
martin@bazaar:~$ sigcheck.py subversion-1.1.3.tar.bz2.asc New key added to /home/martin/.sigcheck Correct signature, history: Never seen this signature before. martin@bazaar:~$
martin@bazaar:~/compile/kernel$ sigcheck.py linux-2.4.28.tar.bz2.sign Correct signature, history: Kernel ftp archive (autosign on upload) 2005-01-19 File linux-2.4.28.tar.bz2 2004-06-26 File patch-2.6.7.bz2 2004-06-26 File patch-2.6.6.bz2 2004-06-26 File patch-2.6.5.bz2 2004-06-16 File patch-2.4.26.bz2 ... 4 more entries martin@bazaar:~/compile/kernel$Here is an sample dot-sigcheck file. You don't need to copy this, yours will get created automatically.