What is the fastest and/or cheapest way to travel between two places in India?
Try 90di.com's online travel search engine. It gets you possible routes by bus, train, flight or train & flight. The best part is (in most cases) you get to view the fare & duration in the search results that are delivered amazingly fast. You can choose to sort on the results by Departure time, Arrival time, Duration, Transits, Fare. The search results contain links to book tickets online through a service provider's website.
You can also send your travel search queries in subject field of email to the emailID 90di.com@gmail.com and you will get your search result in your inbox within minutes. For instance, to check availability of Second Class AC reservation on Coromandal Express (Train # 2841) on 25/Aug/2009, type "AVL train 2841 HWH to MAS on 25/Aug/2009 2A" as your email subject & send.
When is the latest date by which I can get confirmed (or wait-listed) train tickets?
Use Cleartrip's Availability calendar for Indian Railways trains. It shows you availability starting from the current day to the next 3 months.
How to find train or flight info when you don't have access to the Internet?
You can dial 139 from your landline, mobile & CDMA phones for railway inquiries or try Indian Railway's SMS Enquiry Numbers: 57886, 54959, 5676747. I have tried & found Google India's SMS service to be a better proposition. To find the PNR Status, SMS "pnr {number}" to 9-77-33-00000. You can similarly find a train's schedule ("train schedule 2926"), trains between stations ("train delhi to mumbai"), train seat availability ("train avail 1018 Bangalore to Mumbai on 24-04"), train fare ("train fare 1018 Bangalore to Mumbai for SL")
To check the status of flight IT 302, send SMS with the query "it302"
Also see:
Make the most of IRCTC
E-Commerce in India