PNC's and PMC's
Not only are PNC's (Philatelic Numismatic Covers) nice to look at, but they are an excellent way to get Uncirculated coins! Usually low mintage, and sometimes the only way to get a certain coin, is by getting the PNC release!
PMCs (Philatelic Medallic Covers) are similar to Philatelic Numismatic Covers, but contain a medallion or medal as opposed to a coin. These medallions can be quite large, often with very colourful or unique designs.
Australia currently has 6,990 Australia Post locations (4,429 metropolitan retail outlets, and 2,561 retail outlets in rural & remote areas). This means that for PNC/PMC releases of 7,500, there is approximately 1.07 of each release available nationwide via these outlets!