[Breadcrumbs is a series on the Marian's Roots & Rambles blog that looks at ways to leave tangible breadcrumbs behind for your future descendants to find.]
I can only speak about town government in New England. Hopefully you'll find something similar in your area, at least in regards to leaving archival records.
Much of New England runs on the concept of town government. Some of the positions are elected and some are appointed. The appointed positions are volunteer and there is often ample opportunity for the average town resident to get involved.
The role of town manager, mayor, selectmen are demanding high responsibility jobs. You would have to be very interested in town government to take on one of these positions. There are, however, many other positions that are less demanding and very fulfilling. Consider participating in the local historical commission or the local cemetery commission. Both of these groups have direct impact on the preservation of history within town. I happen to hold positions on both my local historic and cemetery commission.
When it comes to leaving a trace behind, the key benefit about government is that it documents everything. There is a lengthy paper trail from meeting minutes, to executive decisions and project reports.
The icing on the cake, at least in New England, is the annual town report. If you are a member of a board or commission in a New England town then your name will be included in the town report. Not only will your ancestor find your name included but the annual report also acts as a mini census. You see, in order to hold an elected or appointed town government position you need to be a resident of the town. Not only will your descendant find a trace of you in a particular year, they will also know that you were resident of the specific town.
Getting involved in town government provides a double bonus in helping your descendants find you! Now get out there and get involved!