The Nokia Asha supports quad-band GSM/EDGE and dual-band 3G networks. HSPA is supported too, you get HSDPA speeds up to 7.2Mbps and HSUPA up to 5.76Mbps.
Then there's Wi-Fi b/g/n, which will get you fast data speeds and it doesn't eat into your data plan. Bluetooth 3.0 with EDR handles things like wireless handsfree dongles but also local file sharing.
The Asha 503 uses a microUSB port for both data connections and charging. There is no USB on-the-go support, though.
The 503 also has a memory card slot (and a complimentary 4GB microSD card). Coupled with a card reader it can usually give you the fastest data transfer rates.
And finally, there's the standard 3.5mm audio jack.
The Asha 503 has Wi-Fi and 3G connectivity. The latest Nokia Xpress browser uses server-side compression so it offers a good experience on EDGE and 3G networks.
There's tabbed browsing and you can save favorite websites as tiles in an Opera-like speed dial.
There's a neat start page with categories such as Featured, Mail, Sports, Social Networks, Entertainment, etc. The pull-up context menu gives you quick access to recent, favorites, downloads, web apps and more.
The settings of the browser let you choose the quality of the preloaded images, from lower to best quality. Images can be disabled altogether too. There's a password manager as well.
The browsing experience isn't spectacular on the Asha 503. Pages load reasonably fast but don't look their best on the tiny 3-incher of QVGA resolution. Still, the Asha 503 will certainly let you check the score of your favorite team's last game or browse through the news websites.