This is a question for Big Joe mostly.
that's new, I'm getting called on for actual information
In my city there are about 25 mosques:
http://www.salatomatic.com/sub/Canada/Alberta/Edmonton/w3NnWVwH2C
How come so many? I realise that one reason would simply be geography within the city and size of the community. Obviously people don't really want to drive more than about half an hour, but that doesn't explain why 2 mosques might be side by side, and some are really close to each other.
There are a lot of factors. Much like churches sometimes it is just 2 organizations that aren't working with each other and are competing. Unfortunately this is usually driven mostly by greed of whoever founds the Masjid (actual name of Mosque). But there can be several other reasons. some include:
1. The population of Muslims in an area and the inability for 1 Masjid to handle the population. For daily prayers, it isn't uncommon in my area to see 100+ people at once. On Friday Jummah (think Christian Sunday Congregation) there could be 500-1000 people or more, and Ramadan can pull crowds nearly this size as well. During Eid Prayer it isn't uncommon at some Masjids to have 1500+ people come to pray all at once. Here in Houston, TX the largest organization ISGH organizes with the NFL to rent out the NRG Stadium (where the Texans play) to handle the large crowds and alleviate some of the congestion at Masjids all over the city. Most Masjids that I have been to are set up to hold about 200 people, larger ones 500 (maybe 750 with the Sister's side)
2. There are some that are purely for preference. We have a large Indo/Pakistani/Bangladeshi population here so most ISGH Masjids are centered around the Desi (Indo/Pak/Beng) and Arab cultural ties. When Iftar is served during Ramadan it is commonly Biryani (delicious BTW). There are many smaller Masjids usually in strip malls, etc. that are tied to African cultural groups, such as Somali, Kenya, Sudanese, etc. that aren't part of the larger ISGH organization. There are a couple Turkish oriented Masjids here in Houston as well that are fairly big.
3. There are some sect differences for some. Although Shi'a usually don't have an issue attending daily prayers and some other functions at Sunni oriented Masjids, they also have their own Masjids for Shi'a specific practice. The Turkish Masjid near me (my wife being Turkish I love the ambiance) is highly Sufi oriented although it is predominately occupied by Sunnis. There is also 2-3 Nation of Islam Masjids (sorry I'm cringing even including this movement in as Muslims) in the City as well. MAS (Muslim American Society) also has a few Masjids, but tend to be closely tied with ISGH and the ever popular (here in the US anyway) CAIR.
Are there language differences to consider?
Most Masjids have an Arabic portion which is short and a English main operation During Jummah. Daily prayers are pretty universal in Arabic.I've been to Jummah once at the Turkish Masjid, but it was when they had a visiting Imam from Turkey, He didn't speak a word of English, so I didn't get much out of it. This isn't common anywhere though.
So how could I tell anything at all about one, besides that? Is there unique architecture by sect or country for example?
Honestly unless the Sign says Shia or Sufi or Nation of Islam, you can assume it is Sunni. More than likely a mix of people pray there anyway. There will be a general national groups in each Masjid, much as I said before just due to families and such feeling more close when able to communicate with each other in their native tongue. In Islam it is mandatory not to discriminate and every Muslim prays shoulder to shoulder, toe to toe, regardless of national, race, or financial status. A Sultan is supposed to stand next to a slave if that is where he falls in line. I am quite often easy to notice in a crowd of Muslims, but I have attended several Masjids and never gotten an evil look from anyone.
