You can also use ST_MakePoint which is probably cleaner as you don't have to concatenate latitude and longitude values as text. Use it in conjunction with ST_SetSrid to set the coordinate reference system to 4326, eg,
Select ST_SetSrid(ST_MakePoint(lon, lat),4326) from sometable;
will return a geometry type. Note the order is lon/lat (x/y), a cause of lots of confusion, due to people saying lat/lon in everyday speech.
ST_GeomFromText is generally more useful when you have a geometry in Well-known text (WKT) format, eg,
Select ST_GeomFromText('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0))', 4326);
If your data is actually in the form ((-79.4609576808001,43.9726680183837)) and you don't want to split it up as I suggested above, the correct format to use use with ST_GeomFromText for a point is:
Select ST_GeomFromText('POINT(-79.4609576808001 43.9726680183837)', 4326)
where the SRID is optional, but recommended.
See http://en.wikipedia.org/wiki/Well_Known_Text for more information.