Applying for the e-Tourist Visa wasn't too difficult. After submitting the application and making the payment online, I received an approval e-mail within 36 hours.
I arrived in DEL last week at around 9:30pm on a weekday. There were 2 queues for the e-Tourist Visa counters and I joined the shorter queue (which was a mistake as the longer queue was moving more quickly). There were only 4 people in front of me in the queue, but I waited 45 minutes (!) as it took ages for the immigration officials to process their passport/e-Tourist Visa and take their photo and fingerprints (I think it was due to technical difficulties with their computer systems).