At my department at college, we had to type a lot of tamil text, to send to news papers or government officials. We were having a lot of trouble with that, and had to annoy the office assistant very often to get this done. So, I wrote a web app using javascript to transliterate text from English to Tamil. All typing can be done on this page, and formatting can be done with your favourite word processor. Click here to check it out. The code is highly unorganised and unoptimised :(. You may check the code and ask me if you have trouble understanding it.
Uyir letters can be created using the following sequences

1. அ - a
2. ஆ - aa
3. இ - i
4. ஈ - ii
5. உ - u
6. ஊ - uu
7. எ - e
8. ஏ - ee
9. ஐ - ai
10. ஒ - o
11. ஓ - oo
12. ஒ - au

Here’s the sequence for the Mei letters

1. க - ka
2. ங - nga
3. ச - ca
4. ஜ - ja
5. ஞ - nya
6. ட - ta
7. ண - nha
8. த - tha
9. ந - na
10. ன - nna
11. ப - pa
12. ம - ma
13. ய - ya
14. ர - ra
15. ற - rha
16. ல - la
17. ள - lha
18. ழ - zha
19. வ - va
20. ஷ - sha
21. ஸ - sa
22. ஹ - ha

Try these examples:

• thamizh
• sahasranaamann
• nanhpann
• puutu
• verhrhi
• meerhppaarvai
• poorkkalham

If you have trouble typing a particular word, or if you find a bug, please let me know. Have fun typing!