Series of icons wanted for iPhone app

Lost on Campus

We are developing an iPhone mapping app to help students at large universities find there way around campus.

We need a set of 21 icons designed to represent our different place categories. You don't need to submit all 21 icons at first, send a few examples and we'll comment on the style.

The icons will be used in three main ways within the iPhone app
- Lists
- Map markers
- Image placeholders (where no photo exists)

The categories:
- Lecture theatres
- Buildings
- Rooms
- Female toilets
- Male toilets
- Disabled toilets
- Coffee
- Food
- Bars
- Uni services
- Offices
- Parking
- Sport
- Computers
- Shops
- ATMs
- Accommodation
- Landmarks
- WiFi hotspots
- Printing
- Secret places

Dimensions:
- 400x400 pixels
- Must look good at 40 x 40 pixels

Transparency:
The background of each icon must be transparent so any background image/gradient will show through.

Colours:
The icons are to be mainly black with orange highlights. We're not sure if we want a solid or gradient orange:
- Solid orange: RGB(98, 48, 5)
- Gradient: RGB(100,40,0) - RGB(97, 58, 11)

Overall design:
- We need all the icons to be simple because they need to be shown small sometimes.
- Please view the iPhone image which shows the main menu of our app - we want the icons to work into this design.

File formats (for the winning designs):
- The finished designs should be separate uncompressed PNG images at a minimum.
- Photoshop or vector files would be useful (depending on what program you use to create them).