I just had to mention, the images that TerryB has taken show the potential for amateur photometry with small apertures,
By using the standard photometric filters and exposures, as per TerryB, it is possible to get quite accurate stellar magnitudes (to within 0.01 mag) in the UBVIR ranges. These can be used to get a (B-V), (U-B) and (R-I) index for accurate spectral type analysis.
www.britastro.org/vss/ccd_photometry.htm
This is a very well written introduction to photometry by Norman Walker.
Software like AstroArt 4, CCDSoft etc have photometric capablities.